A facile confined solid-state seed-mediated alloying strategy is applied for the rational synthesis of supported Au–Ni bimetallic nanoparticles (BMNPs). The method sequentially deposits nickel salts and AuNP seeds into the ordered array of extra-large mesopores (EP-FDU-12 support) followed by a high-temperature annealing process. The size, structure, and composition of the AuNi BMNPs can be well tuned by varying the AuNP seeds, annealing temperature, and feeding ratio of metal precursors. Kinetic studies and DFT calculations suggest that the introduction of the Ni component can significantly prompt the O2 activation on AuNPs, which is critical for the selective alcohol oxidation using molecular O2 as the oxidant. The optimal Au–Ni BMNP catalyst showed the highest turnover frequency (TOF) (59 000 h–1, 240 °C) and highest space-time yield (STY) of benzyl aldehyde (BAD) productivity (9.23 kg·gAu–1·h–1) in the gas-phase oxidation of benzyl alcohol (BA), which is at least about 5-fold higher than that of other supported Au catalysts.Keywords: activation of oxygen; Au−Ni bimetallic nanoparticle; bimetallic nanophase diagram; gas-phase selective oxidation of alcohol; solid-state synthesis;

Metal nanodendritic structures have attracted a lot of attention because of their high activity toward catalytic reactions. Herein, we present a facile method for the one-pot synthesis of highly branched PtCu alloy nanodendrites. The composition of the PtCu nanodendrites can be easily tuned by changing the molar ratio of the precursors. The PtCu nanodendrites exhibit efficient catalytic activity toward the methanol oxidation reaction (MOR). Particularly, the Pt1Cu1 nanodendrites exert 4.6× increase in the specific activity and 3.8× increase in the mass activity compared to the commercial Pt/C catalyst. The mechanism of the enhancement was comprehensively studied. The enhanced catalytic activities can be ascribed to the high index surface of the branched structure and the electronic effect between the alloy metals. Specifically, the addition of Cu downshifts the binding energy of Pt, increasing the CO-tolerance ability of PtCu nanodendrites and, hence, improves their MOR activities. Moreover, the PtCu nanodendrites display better stability and durability for MOR compared to Pt/C. The approach can be adapted to synthesize desired Pt-based nanodendrites for various catalytic reactions.

Molecular hydrogen is one of the essential reactants in the chemical industry, and its generation from renewable sources such as biomass materials and water is of great benefit to the future society. Generally, molecular oxygen should be pre-eliminated in the hydrogen evolution reactions (HERs) in order to avoid the reverse hydrogen oxidation reaction (HOR). Here, we report a highly efficient HER from a formaldehyde/water mixture using MgO supported Ag nanoparticles (AgNPs/MgO) as the catalyst and molecular oxygen as a promoter. The HER rate depends almost linearly on the oxygen partial pressure, and the optimal turnover frequency (TOF) of the silver catalyst exceeds 6,600 h–1. Based on the experimental and theoretical results, a surface stabilized MgO/Ag–•OOH complex is suggested to be the main catalytically active species for the HER.Keywords: Ag; formaldehyde; hydrogen evolution reaction; MgO; oxygen promotion;

A good knowledge of nanophase diagrams is critical to understanding the performance of nanomaterials. Herein, we for the first time fabricate a AuPdPt ternary nanophase diagram at 800 °C by experimental means. The solid-state synthesis strategy enables a precise synthesis of AuPdPt trimetallic nanoparticles with a full range of compositions and desired size distributions. By studying the phase behavior of those TMNPs, we succeed in mapping out the boundary curve and tie lines. Interestingly, the AuPdPt nanophase boundary shifts obviously to the Au-rich region as compared to the case of the corresponding bulk diagram, likely due to the combination of size and composition effects. Besides, owing to the different solubility of Pd in Au-rich and Pt-rich matrix, some tie lines do not parallel the baseline. These observations greatly improve our basic understanding of nanophase diagrams and are expected to be valuable references for other systems. Moreover, the as-fabricated nanophase diagram is successfully applied to guide the optimization of AuPdPt TMNPs catalysts for n-hexane oxidation.

Base-free hydrogen evolution from formaldehyde solution represents one of the most important reactions in the fuel cell based hydrogen economy. However, limited progresses have been made in the rational design of cheap and efficient heterogeneous catalysts for this reaction. Here, we for the first time propose a Lewis acid–base combination strategy to design efficient heterogeneous catalysts for HER from HCHO/H2O. By utilizing the Lewis acid/base properties of Bi(NO3)3·5H2O/ZnO, we successfully fabricated core–shell structured ZnO@Bi(NO3)3 composites. A strong interfacial electronic interaction between ZnO and Bi(NO3)3·5H2O is evidenced by the unprecedented 3.3 eV upshift of Zn 2p and 0.5 eV downshift of Bi 4f, which boosts the HER activities of inert ZnO and Bi(NO3)3·5H2O. Destroying the interfacial electronic interaction leads to a fast deactivation while increasing interfacial sites proportionally enhances the activity, indicating that interfacial sites are real active sites. DFT calculations confirm that ZnO@Bi(NO3)3 composites greatly lower the activation barrier of H2 formation from two adsorbed H atoms and thus promote the H2 production. The Lewis acid–base combination strategy also applies to the TiO2@Bi(NO3)3 system, further highlighting the importance of salt–metal oxide interface in heterogeneous catalysis.

The development of efficient catalyst for oxidative coupling of methane (OCM) reaction represents a grand challenge in direct conversion of methane into other useful products. Here, we reported that a newly developed combinatorial approach can be used for ultrafast optimization of La2O3-based multicomponent metal oxide catalysts in OCM reaction. This new approach integrated inkjet printing assisted synthesis (IJP-A) with multidimensional group testing strategy (m-GT) tactfully takes the place of conventionally high-throughput synthesis-and-screen experiment. Just within a week, 2048 formulated LiMgMnOx-La2O3 catalysts in a 64·8·8·8·8 = 262 144 compositional space were fabricated by IJP-A in a four-round synthesis-and-screen process, and an optimized formulation has been successfully identified through only 4·8 = 32 times of tests via m-GT screening strategy. The screening process identifies the most promising ternary composition region is Li0–0.48Mg0–6.54Mn0–0.62-La100Ox with an external C2 yield of 10.87% at 700 °C. The yield of C2 is two times as high as the pure nano-La2O3. The good performance of the optimized catalyst formulation has been validated by the manual preparation, which further prove the effectiveness of the new combinatorial methodology in fast discovery of heterogeneous catalyst.Keywords: high-throughput; inkjet printing; multidimensional group testing; oxidative coupling of methane;

•Pt/TiO2 shows good performance in non-photocatalytic oxidation of benzyl alcohol.•Water is employed as green solvent.•Ambient air is employed as green oxidant.•The activity of Pt/TiO2 is linearly related to the anatase ratio of TiO2 support.•Higher anatase content results in better performance.Pt nanoparticles supported on anatase TiO2 is an efficient and stable catalyst for room-temperature selective oxidation of benzyl alcohol under base-free aqueous conditions with ambient air as the oxidant. The result shows that the anatase content of support has a big influence on the activity of Pt/TiO2. Higher anatase content results in better performance, with optimal activity for Pt/anatase TiO2 of 76.7 ± 1.5% in conversion and nearly 100% in selectivity to aldehyde within 10 h. Moreover, a quasi-linear relationship between anatase content of the support and the activity of Pt/TiO2 is observed.Download high-res image (120KB)Download full-size image

AgPd alloy nanoparticles deposited on carbon nitride have been synthesized by a facile one-step reduction method and exhibit high catalytic activity at near room temperature (30 °C) for formic acid dehydrogenation, both under visible light and in darkness. The study proves that using the synergistic combination of alloying effects and metal-support interactions greatly enhances the catalytic activity of Pd-based nanocatalysts for hydrogen generation.

Novel Pt/Bi2O3−x catalysts synthesized by reduction of Pt/Bi2O3 in an H2 atmosphere at 300 °C were found to be efficient (conversion of 94.1 ± 2.7%, selectivity to aldehyde >99%) for benzyl alcohol oxidation to benzaldehyde at room temperature (26 °C) under base-free aqueous conditions. The catalytic oxidation is a green-chemistry compatible process with atmospheric O2 as the oxidant at ambient pressure. The high catalytic activity of Pt/Bi2O3−x is ascribed to the synergistic effect between Pt0 and nearby partially reduced Bi2O3−x species. Pt0 acts as a site to cleave the α-C–H bond of alcohols while Bi2O3−x could facilitate the activation of oxygen.

Novel Pt/Bi2O3−x catalysts synthesized by reduction of Pt/Bi2O3 in an H2 atmosphere at 300 °C were found to be efficient (conversion of 94.1 ± 2.7%, selectivity to aldehyde >99%) for benzyl alcohol oxidation to benzaldehyde at room temperature (26 °C) under base-free aqueous conditions. The catalytic oxidation is a green-chemistry compatible process with atmospheric O2 as the oxidant at ambient pressure. The high catalytic activity of Pt/Bi2O3−x is ascribed to the synergistic effect between Pt0 and nearby partially reduced Bi2O3−x species. Pt0 acts as a site to cleave the α-C–H bond of alcohols while Bi2O3−x could facilitate the activation of oxygen.

Catalytic selectivity for producing an ideal product is a key topic for chemical transformations through heterogeneous catalysis. Tuning catalytic selectivity by integrating the second metal to form an alloy has been well demonstrated in the literature. Here we report a method to tune catalytic selectivity in oxidative catalysis on another category of heterogeneous catalysts, transition-metal oxides. By choosing the oxidative dehydrogenation (ODH) of ethane to ethylene as a probe reaction, we demonstrated that doping nonmetallic atoms to the surface lattice of catalyst of a transition-metal oxide can enhance catalytic selectivity through suppression of complete oxidation of the reactant molecules. Catalysts of Co3O4 with doped silicon atoms (Six-Co3O4) maintaining the spinel structure of pure Co3O4 exhibit much higher selectivity for the production of ethylene through ODH of ethane in comparison to pure Co3O4 at 600 °C by 40%. The suppression of activity of surface lattice oxygen atoms was evidenced by the observation that the surface lattice oxygen atoms of Six-Co3O4 cannot exchange oxygen atoms with gas-phase oxygen at low temperatures while pure Co3O4 can. The difference in releasing surface lattice oxygen atoms and dissociating molecular oxygen between pure Co3O4 and Six-Co3O4 was supported by DFT calculations. The calculated activation barriers for dissociation of molecular O2 and energy barriers for hopping surface oxygen vacancies of Six-Co3O4 are obviously higher than those of pure Co3O4, respectively. These experimental exploration and computational studies established a correlation between increase of catalytic selectivity and suppression of the activity of surface lattice oxygen atoms/oxygen vacancies. This correlation suggests an approach for increasing the catalytic selectivity of oxidative catalysis through suppressing activity of surface lattice oxygen atoms/vacancies via doping atoms of a nonmetallic element. This new approach was further confirmed by the observed higher catalytic selectivity for production of ethylene on Ge0.2-Co3O4 in comparison to pure Co3O4.Keywords: catalytic selectivity; cobalt oxide; ethane; ethylene; oxidative dehydrogenation; oxygen vacancies; surface lattice oxygen

Previous cyanation processes always involved the use of hypertoxic CN− ions or UV-light, which is health-risky and energy-wasting. For the purpose of environment-friendly chemistry, we introduced a general Fenton-reaction synthesis of metal cyanide solids using acetonitrile as a green cyanide source. This Fenton-improved cyanation method gets rid of CN− ions and UV-light efficiently, which is green and facile.

A calcium(II) exchanged zeolite Y (Ca-Y) was prepared and evaluated in ethanol–HCl induced gastric ulcer using a mice model. Benefiting from the high procoagulant activity, good resistance to gastric fluid and anti-acid capability of Ca-Y, a significantly reduced ulcer area percentage from 35.1% ± 4.4% to 11.5% ± 1.9%, was achieved at an oral dosage of 5.0 g kg−1, along with an increased intragastric pH from 2.0 ± 0.5 to 4.5 ± 0.5.

A new ·CN radical molecular surface chemisorption strategy was developed to modify Pt/C electrocatalysts in a green and facile manner via a photo-Fenton cyanation process. After the surface modification, the Pt/C electrocatalysts display better specific activity for ORR and a significantly enhanced methanol (MeOH)-tolerant property in both alkline and acidic media. The experimental observations and DFT calculations suggest that the unique electrochemical performance of CN–Pt/C might be derived from the covalent nature of the interaction between ·CN and Pt surface. In particular, it hinders the formation of detrimental OHad–K+(H2O)x, CN–K+(H2O)x, or CN–Na+(H2O)x clusters on the surface of PtNPs, which could block the access of oxygen molecules. Meanwhile, the adsorption of MeOH molecules becomes more difficult as compared to unmodified Pt in KOH solution on the basis of the DFT calculations, making CN–Pt/C an efficient cathode electrocatalyst to alleviate the MeOH crossover problem in alkaline DMFCs. Interestingly, experimental results show that the steric blocking effects of CN groups also improve MeOH-tolerant property CN–Pt/C catalysts operated in acid medium. The green nature and simplicity of the current strategy can facilitate their large-scale use to modify the Pt electrocatalysts with improved performance.

Fast optimization of mesoporous ternary metal oxide (CuCeZrOw) catalysts for n-hexane oxidation is achieved via a newly developed combinatorial approach based on ink-jet printing assisted synthesis and multi-dimensional group testing.

•Inkjet printing synthesis has emerged as a useful technique for fabricating functional metal oxides.•Special ink formulations for IJP synthesis of functional metal oxides were overviewed.•IJP techniques used in inorganic and heterogeneous catalysts, sensors were summarized.Inkjet printing (IJP) synthesis has emerged as a useful technique for the fabrication of functional metal oxides in the fields of nanotechnology and materials science. In this paper, we will review the fundamental state-of-the-art principles of the special ink formulations used for IJP synthesis of functional metal oxides and the applications of these oxides.

The design and preparation of efficient, stable and economical supported multi-metallic nanoparticles (MMNPs) has been a major direction in many applications especially in the catalysis area. The conventional methods for MMNP synthesis are generally complex and lack tight control over the composition. Herein, we report a simple and general method for the synthesis of MMNPs within extra-large three-dimensional mesoporous titania (EP-TiO2), based on a one-step, versatile in situ photo-deposition process. The successful simultaneous photo-deposition of multi-metallic precursors allows us to synthesize a series of supported MMNPs (AuPt/AuPd/PtPd/AuPtPd). The composition of MMNPs can be easily controlled by changing the initial molar ratio of metal precursors. Furthermore, the metal alloying process is carried out under low-temperature annealing in air, which benefits from the extra-large mesoporous networks of EP-TiO2 with significantly reduced particle-migration probability. For AuPt/EP-TiO2, a homogeneous alloy structure is obtained after annealing at 350 °C, with Au50Pt50 showing optimum activity in the catalytic combustion of n-hexane. It is expected that the one-step in situ photosynthesis of MMNPs within mesoporous materials has profound implications toward the design of better catalytic nano-architectures.

Sub-10 nm AuPtPd alloy trimetallic nanoparticles (TMNPs) with a high oxidation-resistant property were prepared by photo-deposition followed by a high temperature (700–900 °C) air annealing process.

Platinum nanoparticles supported on Ca(Mg)-ZSM-5 is an efficient, highly selective and stable catalyst for room-temperature oxidation of alcohols in water. Based on in situ EPR measurement and the radical trapping technique, we propose that the generation of ˙OH radicals by cleavage of the O–O bond in the H2O2 intermediate is the rate determining step, which participated in the abstraction of H from the α-C–H bond of alcohol molecules to produce aldehydes/ketones.

We show here a new reaction between lead(II) oxide and formaldehyde aqueous solution, which has been overlooked all along. The special structure of the new substance (PbCH2O2) and the DFT calculations suggest a diol-mechanism, which not only informs people about the corrosive nature of HCHO toward Pb and PbO, but also leads us to discover some new reactions between a variety of vicinal diol-type molecules and PbO. The reaction is further highlighted because of its potential application in detection and treatment of formaldehyde-containing wastewaters.

A thermal and hydrothermal stable mesoporous ceramic acid (mCA) was synthesized by uniform coating of a WZrOx layer onto the internal surface of extra-large mesoporous silica (EP-FDU-12). Its ordered mesoporous structure and strong Brönsted acid sites display excellent thermal (1000 °C, air, 5 h) and hydrothermal (water steam, 300 °C, 24 h) stability.

A solid phase metallurgy strategy is applied to synthesize Au–Pd and Ni–Pd bimetallic nanoparticles (BMNPs) with a tight sub-5 nm particle size distribution. The near-surface elemental composition and redox properties of Au–Pd BMNPs can be well tailored, which leads to an optimized catalytic performance in n-hexane combustion.

Well-dispersed bimetallic nanoparticles (BMNPs = PtPd/AuPd/AuPt) confined in mesoporous metal oxides (MMOs = TiO2/Al2O3/SiO2/ZrO2) are synthesized by a general and mild one-step sol–gel strategy. This approach allows facile control over the compositional parameter of the supported BMNPs and the MMOs. Moreover, we can also control the formation of the alloy by simply adjusting the loading content. The catalytic results of PtPd–MMO composites in the hydrogenation of nitrobenzene have shown that the performance is highly composition-dependent and support-dependent with Pt1Pd3–m-SiO2 showing the optimum activity.

Herein, we report a newly developed mesoporous VOx-CeO2 catalyst with dominant monomeric VOx species, which can promote the gas-phase ODH reaction of benzyl alcohol-to-benzaldehyde (BA-to-BAD) by molecular oxygen at a surprisingly low temperature range of 203–243 °C, with a high mass-specific activity of ∼25 mmol·gcat–1·h–1 and TOF of 1367 h–1. To the best of our knowledge, it appears to be the most effective transition metal oxides catalyst for the BA-to-BAD reaction in the gas phase. Experimental measurements and density functional theory (DFT) calculations suggest that the activities of VOx-CeO2 catalysts strongly depend on the polymeric states of surface VOx, with monomeric VOx giving much better performance than bigger VOx clusters. It is important to highlight that a specific monomeric VO3 species, only occurring under the reaction conditions, is identified for the first time to have the key influence on BA oxidation. Moreover, it has been found that the origin for the unique activity of such monomeric VOx-CeO2 can be attributed to its electronic “hole” structure.

Adsorption of plasma proteins to nanomaterial surfaces has a great influence on their bio-functionality. However, there is limited understanding of the relationship between the functional proteins in the protein corona and the biological identity of the materials. Here we show that the in situ generated thrombin in the protein corona of a Ca-zeolite surface displays a calcium-dependent, unusually high (∼3,000 NIH U/mg) procoagulant activity, which is even stable against antithrombin deactivation. Removing the encapsulated Ca2+ in the zeolites leads to deactivation by antithrombin. Our observations suggest that the thrombin activity can be regulated by the inorganic surface and cations. Most importantly, our discovery indicates the link between the biomolecules in the protein corona and the procoagulant activity of the materials, providing a new molecular basis for the procoagulant mechanism for zeolite hemostatics.

Unexpected, excellent antisintering property of highly loaded AuNPs is observed when extra-large mesoporous silica EP-FDU-12 (cage size >25 nm) is used as the supports. The average particle size of the entrapped AuNPs after 550 °C calcination approaches 25.6 ± 5.2 nm at the gold loading amount of 5.0 wt %, but it greatly reduces into only 5.6 ± 1.2 nm as the metal loading reaches up to 26.1 wt %. It is demonstrated that the unique three-dimensional porous structure of EP-FDU-12 makes particle-migration difficult to occur and thus prevents direct particle–particle aggregation. This further allows two or more AuNPs to be encapsulated in every extra-large cage at high particle concentrations (10–35 wt %), which enables interparticle interactions via significant overlapping of the diffusion-spheres of AuNPs. As a result, atom-migration via vapor from cage to cage is largely shut off and local vapor-particle equilibrium within each cage is possible, leading to a successful stable AuNPs/mesoporous silica system.Keywords: antisintering property; gold nanoparticle; interparticle interaction; mesoporous silica;

RuO2–Au composite nanoparticles (RuO2–Au CNPs) are synthesized via a simple calcination of RuNPs and AuNPs encapsulated within extra-large mesocages of mesoporous silica (EP-FDU-12). Both the Ru/Au ratio (0.02:0.2) and the nanostructure of the mesoporous supports are critical for its successful formation. Surface-enhanced Raman scattering (SERS) effects are observed for RuO2 composite because of the interaction between RuO2 and Au of the RuO2–Au CNPs. The nanocontact modifies the electronic and chemical properties of Au and RuO2, respectively, which in turn benefits their catalytic performance with enhanced activities and reduced coking-deposition content in gas-phase cyclohexanol-selective oxidation.Keywords: composite nanoparticle; mesoporous support; nanocontact; RuO2−Au;

Mesoporous non-silicate oxides (MNSOs), with well-defined organization on the 2–50 nm size scale, may play a pivotal role in advancing vital disciplines such as catalysis, energy conversion and biotechnology. The vast majority of known MNSOs have a pore size less than 16 nm due to the limited dimensions of the organic templates. Herein, we present a simple and general method for the synthesis of MNSOs with extra-large three-dimensional mesoporous structures, which is based on uniform coating of non-silicate oxide nanoparticle precursors onto the surface of mesoporous silica EP-FDU-12. The successful synthesis of MNSOs relies on two key factors: the extra-large, 3-D open mesoporous networks of the EP-FDU-12 hard-template and the stable NSO nanoparticles formed in AcHE solution. Extra-large pore size and window size are prerequisites to avoid the local aggregation and phase separation of the coating metal oxides. The coating thickness can be easily controlled by changing the initial concentration ratio of raw materials. The successful uniform coating of NSOs in the AcHE sol–gel system allows us to synthesize a large variety of EP-NSOs (EP-Al2O3, EP-TiO2, EP-ZrO2, EP-Ce–TiO2 and EP-K–Ce–TiO2). The EP-Al2O3 and Pd/EP-Al2O3 catalysts have been investigated in the F–C alkylation and n-hexane combustion reactions, which serve as two examples to show that catalytic reactions can benefit from the extra-large, 3-D open mesoporous networks with improved adsorption and diffusion of reactants and designed metal-to-support interfaces.

The design and preparation of efficient, stable and economical metal nanoparticles supported on mesoporous metal oxides (MNPs/MMOs) has been a major direction in many applications especially in the catalysis area. The conventional synthesis methods for MNPs/MMOs are complex and lack high-degree control over different compositional/structural parameters. Herein, we reported a general synthesis of MNP/MMO composites via a one-step, versatile sol–gel process under strongly acidic conditions. The successful introduction of stable, PVP-capped MNPs into the AcHE sol–gel system (Ac, H, and E represent acetic acid, HCl, and EtOH, respectively) allows us to synthesize a large variety of MNPs/MMOs (M = Pt, Au, Pd, and MMOs = TiO2, SiO2, ZrO2, Al2O3). In addition to the compositional variation, the preformed PVP-capped MNPs in the AcHE sol–gel system decouple the particle nucleation and inorganic–organic co-assembly processes, permitting a stabilization of the MNPs in the nano-scale range over a wide particle concentration. Meanwhile, structural regulation can also be achieved by variation of the block copolymer concentration. The high-degree control over different compositional/structural parameters of MNPs/MMOs provides a useful material candidate platform to further study their structure–property relationship for the design of a better catalyst for a specific reaction. The best Pt/Si–TiO2 catalyst for n-hexane combustion obtained in this study serves as an example to show that the control of the adsorption and diffusion of reactants and products may be achieved by the optimization of composition and structure of the MNP/MMO catalysts, which may provide valuable insights for a detailed understanding of the structure- or composition-dependent chemical reactivity of the catalysts.

Ordered, extra-large mesopores with highly loaded gold nanoparticles (AuNPs) exhibits unique sintering- and coking-resistant properties in gas-phase, cyclohexanol selective aerobic oxidation.

It is a challenge to use acetonitrile as a cyanating agent because of the difficulty in cleaving its C–CN bond. Herein, we report a mild photo-assisted route to conduct the cyanation of transition metal nitrates using acetonitrile as the cyanating agent coupled with room-temperature C–C bond cleavage. DFT calculations and experimental observations suggest a radical-involved reaction mechanism, which excludes toxicity from free cyanide ions.

We describe an inkjet printing assisted cooperative-assembly method for high-throughput generation of catalyst libraries (multicomponent mesoporous metal oxides) at a rate of 1 000 000-formulations/hour with up to eight-component compositions. The compositions and mesostructures of the libraries can be well-controlled and continuously varied. Fast identification of an inexpensive and efficient quaternary catalyst for photocatalytic hydrogen evolution is achieved via a multidimensional group testing strategy to reduce the number of performance validation experiments (25 000-fold reduction over an exhaustive one-by-one search).

We show here the first radical route for the direct photosynthesis of AuCN oligomers with different sizes and shapes, as evidenced by TEM observations, from an Au nanoparticle/benzaldehyde/CH3CN ternary system in air under UV-light irradiation. This photochemical route is green, mild, and universal, which makes itself distinguishable from the common cyanidation process. Several elementary reaction steps, including the strong C–C bond dissociation of CH3CN and subsequent •CN radical addition to Au, have been suggested to be critical in the formation of AuCN oligomers based on the identification of •CN radical by in situ EPR and the radical trapping technique, and other reaction products by GC-MS and 1H NMR, and DFT calculations. The resulting solid-state AuCN oligomers exhibit unique spectroscopic characters that may be a result of the shorter Au–Au distances (namely, aurophilicity) and/or special polymer-like structures as compared with gold cyanide derivatives in the aqueous phase. The nanosized AuCN oligomers supported on mesoporous silica showed relatively good catalytic activity on the homogeneous annulation of salicylaldehyde with phenylacetylene to afford isoflavanones employing PBu3 as the cocatalyst under moderate conditions, which also serves as evidence for the successful production of AuCN oligomers.

A strategy for stabilizing ultrasmall gold clusters under thermal treatment has been developed. The essence of this methodology lies in construction of heterostructured transition-metal oxide–mesoporous silica supports. The supported clusters have been demonstrated to be sintering resistant and highly active for catalytic CO oxidation.

A new type of defect-less, layered organo-titanosilicate is synthesized using a simple, template-free, evaporation-induced self-assembly process. The obtained layered material has superhydrophobicity and exhibits promising catalytic activity in the epoxidation of olefins using 30% H2O2 aqueous solution as oxidant at room temperature.

The acidic properties of mesoporous TiO2–SiO2 mixed oxides were evaluated by 31P magic-angle spinning NMR spectroscopy using trimethylphosphine oxide (TMPO) and trimethylphosphine (TMP) as probe molecules. It confirms that mesoporous TiO2–SiO2 has moderate strong Brönsted acid sites. The number of the Brönsted acidic sites can be increased via a high-temperature hydrogenation process, which subsequently improves their catalytic performance in the Friedel–Crafts reaction of anisole and benzyl alcohol.

The surface structure of mesoporous TiO2 is reconstructed via a visible-light-driven reaction with benzyl alcohol molecules at mild, anaerobic conditions, which substantially extends its visible-light absorption and photocatalytic activities.

High-yielding benzyl alcohol-to-benzaldehyde (BA-to-BAD) transformation has been achieved over mesoporous crystalline TiO2 at mild conditions under visible-light irradiation with/without molecular oxygen. DFT calculations show that the antibonding π molecular orbitals (MOs) of BA can hybridize with the O2p atomic orbitals (AOs) of TiO2, leading to the appearance of new energy levels located in the band gap where holes can be generated under visible-light irradiation. However, the oxidative product, BAD, is not stable when adsorbed on TiO2 surface. This fact is supposed to prevent BAD from overoxidation by ceasing the hole formation. As a result, the hole generation becomes controllable in this type of photoreaction system, and a so-labeled “self-adjustable photo-oxidation system” (denoted as SAPS) can be established. In addition, we also found that lattice oxygen (OL) and Ti atoms within TiO2 frameworks serve as the efficient reservoir for hydrogen and electrons in anaerobic reaction.

We demonstrate that supermolecular templating allows tuning the pore size of ordered mesoporous materials in the once elusive range from 30 nm to more than 60 nm through simple control of synthetic variables (salt/supermolecule concentration and hydrothermal temperature). Gold nanoparticles (AuNPs) within the extra-large pores exhibit dramatically increased lifetime compared to those located within relatively small mesopores due to the enhanced mass diffusion that suppresses coke deposition on AuNPs.

Mesoporous TiO2 modified with benzene siloxane displays a capability to generate more hydroxyl radicals upon photo-illumination, which substantially enhances its surface reactivity for the degradation of organic dyes.

A newly developed mesoporous mixed metal oxide (K-Cu-TiO2) catalyst is capable of highly selective, gas-phase benzyl alcoholbenzaldehyde transformation at excellent yields (>99%) under surprisingly low temperatures (203 °C, bp of benzyl alcohol). The low-temperature reaction conditions and integration of K and Cu(I) components into the TiO2 matrix are of vital importance for the stabilization of an active Cu(I) oxidation state and resultant stable, excellent catalytic performance.

The design and preparation of efficient, stable and economical supported multi-metallic nanoparticles (MMNPs) has been a major direction in many applications especially in the catalysis area. The conventional methods for MMNP synthesis are generally complex and lack tight control over the composition. Herein, we report a simple and general method for the synthesis of MMNPs within extra-large three-dimensional mesoporous titania (EP-TiO2), based on a one-step, versatile in situ photo-deposition process. The successful simultaneous photo-deposition of multi-metallic precursors allows us to synthesize a series of supported MMNPs (AuPt/AuPd/PtPd/AuPtPd). The composition of MMNPs can be easily controlled by changing the initial molar ratio of metal precursors. Furthermore, the metal alloying process is carried out under low-temperature annealing in air, which benefits from the extra-large mesoporous networks of EP-TiO2 with significantly reduced particle-migration probability. For AuPt/EP-TiO2, a homogeneous alloy structure is obtained after annealing at 350 °C, with Au50Pt50 showing optimum activity in the catalytic combustion of n-hexane. It is expected that the one-step in situ photosynthesis of MMNPs within mesoporous materials has profound implications toward the design of better catalytic nano-architectures.

The design and preparation of efficient, stable and economical metal nanoparticles supported on mesoporous metal oxides (MNPs/MMOs) has been a major direction in many applications especially in the catalysis area. The conventional synthesis methods for MNPs/MMOs are complex and lack high-degree control over different compositional/structural parameters. Herein, we reported a general synthesis of MNP/MMO composites via a one-step, versatile sol–gel process under strongly acidic conditions. The successful introduction of stable, PVP-capped MNPs into the AcHE sol–gel system (Ac, H, and E represent acetic acid, HCl, and EtOH, respectively) allows us to synthesize a large variety of MNPs/MMOs (M = Pt, Au, Pd, and MMOs = TiO2, SiO2, ZrO2, Al2O3). In addition to the compositional variation, the preformed PVP-capped MNPs in the AcHE sol–gel system decouple the particle nucleation and inorganic–organic co-assembly processes, permitting a stabilization of the MNPs in the nano-scale range over a wide particle concentration. Meanwhile, structural regulation can also be achieved by variation of the block copolymer concentration. The high-degree control over different compositional/structural parameters of MNPs/MMOs provides a useful material candidate platform to further study their structure–property relationship for the design of a better catalyst for a specific reaction. The best Pt/Si–TiO2 catalyst for n-hexane combustion obtained in this study serves as an example to show that the control of the adsorption and diffusion of reactants and products may be achieved by the optimization of composition and structure of the MNP/MMO catalysts, which may provide valuable insights for a detailed understanding of the structure- or composition-dependent chemical reactivity of the catalysts.

Sub-10 nm AuPtPd alloy trimetallic nanoparticles (TMNPs) with a high oxidation-resistant property were prepared by photo-deposition followed by a high temperature (700–900 °C) air annealing process.

Fast optimization of mesoporous ternary metal oxide (CuCeZrOw) catalysts for n-hexane oxidation is achieved via a newly developed combinatorial approach based on ink-jet printing assisted synthesis and multi-dimensional group testing.

A solid phase metallurgy strategy is applied to synthesize Au–Pd and Ni–Pd bimetallic nanoparticles (BMNPs) with a tight sub-5 nm particle size distribution. The near-surface elemental composition and redox properties of Au–Pd BMNPs can be well tailored, which leads to an optimized catalytic performance in n-hexane combustion.

A thermal and hydrothermal stable mesoporous ceramic acid (mCA) was synthesized by uniform coating of a WZrOx layer onto the internal surface of extra-large mesoporous silica (EP-FDU-12). Its ordered mesoporous structure and strong Brönsted acid sites display excellent thermal (1000 °C, air, 5 h) and hydrothermal (water steam, 300 °C, 24 h) stability.

The surface structure of mesoporous TiO2 is reconstructed via a visible-light-driven reaction with benzyl alcohol molecules at mild, anaerobic conditions, which substantially extends its visible-light absorption and photocatalytic activities.

Mesoporous TiO2 modified with benzene siloxane displays a capability to generate more hydroxyl radicals upon photo-illumination, which substantially enhances its surface reactivity for the degradation of organic dyes.

Novel Pt/Bi2O3−x catalysts synthesized by reduction of Pt/Bi2O3 in an H2 atmosphere at 300 °C were found to be efficient (conversion of 94.1 ± 2.7%, selectivity to aldehyde >99%) for benzyl alcohol oxidation to benzaldehyde at room temperature (26 °C) under base-free aqueous conditions. The catalytic oxidation is a green-chemistry compatible process with atmospheric O2 as the oxidant at ambient pressure. The high catalytic activity of Pt/Bi2O3−x is ascribed to the synergistic effect between Pt0 and nearby partially reduced Bi2O3−x species. Pt0 acts as a site to cleave the α-C–H bond of alcohols while Bi2O3−x could facilitate the activation of oxygen.

Novel Pt/Bi2O3−x catalysts synthesized by reduction of Pt/Bi2O3 in an H2 atmosphere at 300 °C were found to be efficient (conversion of 94.1 ± 2.7%, selectivity to aldehyde >99%) for benzyl alcohol oxidation to benzaldehyde at room temperature (26 °C) under base-free aqueous conditions. The catalytic oxidation is a green-chemistry compatible process with atmospheric O2 as the oxidant at ambient pressure. The high catalytic activity of Pt/Bi2O3−x is ascribed to the synergistic effect between Pt0 and nearby partially reduced Bi2O3−x species. Pt0 acts as a site to cleave the α-C–H bond of alcohols while Bi2O3−x could facilitate the activation of oxygen.

AgPd alloy nanoparticles deposited on carbon nitride have been synthesized by a facile one-step reduction method and exhibit high catalytic activity at near room temperature (30 °C) for formic acid dehydrogenation, both under visible light and in darkness. The study proves that using the synergistic combination of alloying effects and metal-support interactions greatly enhances the catalytic activity of Pd-based nanocatalysts for hydrogen generation.

Mesoporous non-silicate oxides (MNSOs), with well-defined organization on the 2–50 nm size scale, may play a pivotal role in advancing vital disciplines such as catalysis, energy conversion and biotechnology. The vast majority of known MNSOs have a pore size less than 16 nm due to the limited dimensions of the organic templates. Herein, we present a simple and general method for the synthesis of MNSOs with extra-large three-dimensional mesoporous structures, which is based on uniform coating of non-silicate oxide nanoparticle precursors onto the surface of mesoporous silica EP-FDU-12. The successful synthesis of MNSOs relies on two key factors: the extra-large, 3-D open mesoporous networks of the EP-FDU-12 hard-template and the stable NSO nanoparticles formed in AcHE solution. Extra-large pore size and window size are prerequisites to avoid the local aggregation and phase separation of the coating metal oxides. The coating thickness can be easily controlled by changing the initial concentration ratio of raw materials. The successful uniform coating of NSOs in the AcHE sol–gel system allows us to synthesize a large variety of EP-NSOs (EP-Al2O3, EP-TiO2, EP-ZrO2, EP-Ce–TiO2 and EP-K–Ce–TiO2). The EP-Al2O3 and Pd/EP-Al2O3 catalysts have been investigated in the F–C alkylation and n-hexane combustion reactions, which serve as two examples to show that catalytic reactions can benefit from the extra-large, 3-D open mesoporous networks with improved adsorption and diffusion of reactants and designed metal-to-support interfaces.

A strategy for stabilizing ultrasmall gold clusters under thermal treatment has been developed. The essence of this methodology lies in construction of heterostructured transition-metal oxide–mesoporous silica supports. The supported clusters have been demonstrated to be sintering resistant and highly active for catalytic CO oxidation.

A new type of defect-less, layered organo-titanosilicate is synthesized using a simple, template-free, evaporation-induced self-assembly process. The obtained layered material has superhydrophobicity and exhibits promising catalytic activity in the epoxidation of olefins using 30% H2O2 aqueous solution as oxidant at room temperature.

Ordered, extra-large mesopores with highly loaded gold nanoparticles (AuNPs) exhibits unique sintering- and coking-resistant properties in gas-phase, cyclohexanol selective aerobic oxidation.

We show here a new reaction between lead(II) oxide and formaldehyde aqueous solution, which has been overlooked all along. The special structure of the new substance (PbCH2O2) and the DFT calculations suggest a diol-mechanism, which not only informs people about the corrosive nature of HCHO toward Pb and PbO, but also leads us to discover some new reactions between a variety of vicinal diol-type molecules and PbO. The reaction is further highlighted because of its potential application in detection and treatment of formaldehyde-containing wastewaters.

It is a challenge to use acetonitrile as a cyanating agent because of the difficulty in cleaving its C–CN bond. Herein, we report a mild photo-assisted route to conduct the cyanation of transition metal nitrates using acetonitrile as the cyanating agent coupled with room-temperature C–C bond cleavage. DFT calculations and experimental observations suggest a radical-involved reaction mechanism, which excludes toxicity from free cyanide ions.

Platinum nanoparticles supported on Ca(Mg)-ZSM-5 is an efficient, highly selective and stable catalyst for room-temperature oxidation of alcohols in water. Based on in situ EPR measurement and the radical trapping technique, we propose that the generation of ˙OH radicals by cleavage of the O–O bond in the H2O2 intermediate is the rate determining step, which participated in the abstraction of H from the α-C–H bond of alcohol molecules to produce aldehydes/ketones.

The acidic properties of mesoporous TiO2–SiO2 mixed oxides were evaluated by 31P magic-angle spinning NMR spectroscopy using trimethylphosphine oxide (TMPO) and trimethylphosphine (TMP) as probe molecules. It confirms that mesoporous TiO2–SiO2 has moderate strong Brönsted acid sites. The number of the Brönsted acidic sites can be increased via a high-temperature hydrogenation process, which subsequently improves their catalytic performance in the Friedel–Crafts reaction of anisole and benzyl alcohol.

Well-dispersed bimetallic nanoparticles (BMNPs = PtPd/AuPd/AuPt) confined in mesoporous metal oxides (MMOs = TiO2/Al2O3/SiO2/ZrO2) are synthesized by a general and mild one-step sol–gel strategy. This approach allows facile control over the compositional parameter of the supported BMNPs and the MMOs. Moreover, we can also control the formation of the alloy by simply adjusting the loading content. The catalytic results of PtPd–MMO composites in the hydrogenation of nitrobenzene have shown that the performance is highly composition-dependent and support-dependent with Pt1Pd3–m-SiO2 showing the optimum activity.