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Due to the superior catalytic activity and efficient utilization of noble metals, nanocatalysts are extensively used in the modern industrial production of chemicals. The surface structures of these materials are significantly influenced by reactive adsorbates, leading to dynamic behavior under experimental conditions. The dynamic nature poses significant challenges in studying the structure–activity relations of catalysts. Herein, we unveil an anomalous entropic effect on catalysis via surface pre‐melting of nanoclusters through machine learning accelerated molecular dynamics and free energy calculation. We find that due to the pre‐melting of shell atoms, there exists a non‐linear variation in the catalytic activity of the nanoclusters with temperature. Consequently, two notable changes in catalyst activity occur at the respective temperatures of melting for the shell and core atoms. We further study the nanoclusters with surface point defects, i.e. vacancy and ad‐atom, and observe significant decrease in the surface melting temperatures of the nanoclusters, enabling the reaction to take place under more favorable and milder conditions. These findings not only provide novel insights into dynamic catalysis of nanoclusters but also offer new understanding of the role of point defects in catalytic processes. [ABSTRACT FROM AUTHOR]

The renewable‐electricity‐driven CO2 reduction to formic acid would contribute to establishing a carbon‐neutral society. The current catalyst suffers from limited activity and stability under high selectivity and the ambiguous nature of active sites. Herein, we report a powerful Bi2S3‐derived catalyst that demonstrates a current density of 2.0 A cm−2 with a formate Faradaic efficiency of 93 % at −0.95 V versus the reversible hydrogen electrode. The energy conversion efficiency and single‐pass yield of formate reach 80 % and 67 %, respectively, and the durability reaches 100 h at an industrial‐relevant current density. Pure formic acid with a concentration of 3.5 mol L−1 has been produced continuously. Our operando spectroscopic and theoretical studies reveal the dynamic evolution of the catalyst into a nanocomposite composed of Bi0 clusters and Bi2O2CO3 nanosheets and the pivotal role of Bi0−Bi2O2CO3 interface in CO2 activation and conversion. [ABSTRACT FROM AUTHOR]

Improving the stability of sensitive catalytic systems is an emerging research topic in the catalysis field. However, the current design of heterogeneous catalysts mainly improves their catalytic performance. This paper presents a single‐atom catalyst (SAC) strategy to improve the cobalt‐catalysed fluorination of acyl chlorides. A stable Co−F intermediate can be formed through the oxidative fluorination of Co1−N4@NC SAC, which can replace the unstable high‐valent cobalt catalytic system and avoid the use of phosphine ligands. In the SAC system, KF can be employed as a fluorinating reagent to replace the AgF, which can be applied to various substrates and scale‐up conversion with high turnover numbers (TON=1.58×106). This work also shows that inorganic SACs have tremendous potential for organofluorine chemistry, and it provides a good reference for follow‐up studies on the structure‐activity relationship between catalyst design and chemical reaction mechanisms. [ABSTRACT FROM AUTHOR]

Plastics are playing essential roles in the modern society. The majority of them enter environment through landfilling or discarding after turning into wastes, causing severe carbon loss and imposing high risk to ecosystem and human health. Currently, physical recycling serves as the primary method to reuse plastic waste, but this method is limited to thermoplastic recycling. The quality of recycled plastics gradually deteriorates because of the undesirable degradation in the recycling process. Under such background, catalytic upcycling, which can upgrade various plastic wastes into value‐added products under mild conditions, has attracted recent attention as a promising strategy to treat plastic wastes. This Review highlights recent advances in the development of efficient heterogeneous catalysts and useful strategies for upcycling plastics into liquid hydrocarbons, arene compounds, carbon materials, hydrogen, and other value‐added chemicals. The functions of catalysts and the reaction mechanisms are discussed. The key factors that influence the catalytic performance are also analyzed. [ABSTRACT FROM AUTHOR]

Cu–ZnO–Al2O3 catalysts are used as the industrial catalysts for water gas shift (WGS) and CO hydrogenation to methanol reactions. Herein, via a comprehensive experimental and theoretical calculation study of a series of ZnO/Cu nanocrystals inverse catalysts with well-defined Cu structures, we report that the ZnO–Cu catalysts undergo Cu structure-dependent and reaction-sensitive in situ restructuring during WGS and CO hydrogenation reactions under typical reaction conditions, forming the active sites of CuCu(100)-hydroxylated ZnO ensemble and CuCu(611)Zn alloy, respectively. These results provide insights into the active sites of Cu–ZnO catalysts for the WGS and CO hydrogenation reactions and reveal the Cu structural effects, and offer the feasible guideline for optimizing the structures of Cu–ZnO–Al2O3 catalysts. Identification of active sites of a catalyst is the Holy Grail in heterogeneous catalysis. Here, the authors successfully identify the CuCu(100)- hydroxylated ZnO ensemble and CuCu(611)Zn alloy as the active sites of Cu-ZnO catalysts for water gas shift and CO hydrogenation reactions, respectively. [ABSTRACT FROM AUTHOR]

• The active Pd species is uniformly dispersed into MOFs via in-situ PdTCPP introduction. • Customized design of Pd valence state microenvironment for catalytic active centers. • XPS successfully proves the change in the valence state of the palladium element. • The excellent photocatalytic hydrogen evolution performance. Nowadays, heterogeneous catalysis plays an increasingly important role in industry. However, the traditional heterogeneous catalysts still have some shortcomings in fine structure, such as lack of customization and difficulty in regulation. The multifunction and adjustability of metal-organic framework materials (MOFs) make it easier to realize the customized design of microenvironment, so they have extensive application potential in heterogeneous catalysis reactions. In this article, we obtained a mixed ligand NM-125-PdTCPP by grafting PdTCPP in MIL-125-NH 2 for photocatalytic hydrogen evolution. In addition, we reduced a certain amount of PdⅡ in PdTCPP to Pd0 species through different reduction time in a hydrogen atmosphere, achieving changes in the valence states of guest co-catalysts within the host framework of MIL-125-NH 2 , and further regulating the influence of changes in the valence microenvironment on the photocatalytic hydrogen evolution performance. The catalyst with a reduction time of 1 hour (abbreviated as Pd(1 h)@NM-125) has the best photocatalytic hydrogen evolution effect, reaching 603 μmol g −1· h −1, which is 8.5 times as that of the original sample. This study provided a feasible idea for the regulation of MOFs' microenvironment to adjust the photocatalytic performance. [Display omitted] [ABSTRACT FROM AUTHOR]

Green synthesis of adipic acid from renewable biomass is a very attractive goal of sustainable chemistry. Herein, we report efficient catalysts for a two‐step transformation of cellulose‐derived glucose into adipic acid via glucaric acid. Carbon nanotube‐supported platinum nanoparticles are found to work efficiently for the oxidation of glucose to glucaric acid. An activated carbon‐supported bifunctional catalyst composed of rhenium oxide and palladium is discovered to be powerful for the removal of four hydroxyl groups in glucaric acid, affording adipic acid with a 99 % yield. Rhenium oxide functions for the deoxygenation but is less efficient for four hydroxyl group removal. The co‐presence of palladium not only catalyzes the hydrogenation of olefin intermediates but also synergistically facilitates the deoxygenation. This work presents a green route for adipic acid synthesis and offers a bifunctional‐catalysis strategy for efficient deoxygenation. [ABSTRACT FROM AUTHOR]

Propane dehydrogenation (PDH) has great potential to meet the increasing global demand for propylene, but the widely used Pt‐based catalysts usually suffer from short‐term stability and unsatisfactory propylene selectivity. Herein, we develop a ligand‐protected direct hydrogen reduction method for encapsulating subnanometer bimetallic Pt–Zn clusters inside silicalite‐1 (S‐1) zeolite. The introduction of Zn species significantly improved the stability of the Pt clusters and gave a superhigh propylene selectivity of 99.3 % with a weight hourly space velocity (WHSV) of 3.6–54 h−1 and specific activity of propylene formation of 65.5 molC3H6 gPt−1 h−1 (WHSV=108 h−1) at 550 °C. Moreover, no obvious deactivation was observed over PtZn4@S‐1‐H catalyst even after 13000 min on stream (WHSV=3.6 h−1), affording an extremely low deactivation constant of 0.001 h−1, which is 200 times lower than that of the PtZn4/Al2O3 counterpart under the same conditions. We also show that the introduction of Cs+ ions into the zeolite can improve the regeneration stability of catalysts, and the catalytic activity kept unchanged after four continuous cycles. [ABSTRACT FROM AUTHOR]

Although carbon itself acts as a catalyst in various reactions, the classical carbon materials (e.g., activated carbons, carbon aerogels, carbon black, carbon fiber, etc.) usually show low activity, stability, and oxidation resistance. With the recent availability of nanocarbon catalysts, the application of carbon materials in catalysis has gained a renewed momentum. The research is concentrated on tailoring the surface chemistry of nanocarbon materials, since the pristine carbons in general are not active for heterogeneous catalysis. Surface functionalization, doping with heteroatoms, and creating defects are the most used strategies to make efficient catalysts. However, the nature of the catalytic active sites and their role in determining the activity and selectivity is still not well understood. Herein, the types of active sites reported for several mainstream nanocarbons, including carbon nanotubes, graphene‐based materials, and 3D porous nanocarbons, are summarized. Knowledge about the active sites will be beneficial for the design and synthesis of nanocarbon catalysts with improved activity, selectivity, and stability. [ABSTRACT FROM AUTHOR]

Urea is an important organic pollutants in sewage and needs to be removed for environmental protection. Here, we report defective NiFe2O4 (NFO) nanoparticles with excellent performance for urea electro‐oxidation. The results show that defects can be effectively implanted at the surface of NFO nanoparticles by a facile and versatile lithium reduction method without affecting its main crystal structure and grain size. The defective NFO‐5Li nanoparticles displayed a significantly improved urea electro‐oxidation performance compared with NFO‐Pristine nanoparticles. Particularly, the NFO‐Pristine and NFO‐5Li show a potential of 1.398 and 1.361 V at the current density of 10 mA cm−2 and Tafel slope of 37.3 and 31.4 mV dec−1, respectively. In addition, the NFO‐5Li nanoparticles also revealed outstanding electrocatalytic stability. The superior performance can be attributed to the designed tunable surface defect engineering. Furthermore, the defect engineering strategy as well as the defective NFO nanoparticles hold great potential for applications in other materials and areas. [ABSTRACT FROM AUTHOR]

Abstract: Selective conversion of syngas (CO/H2) into C2+ oxygenates is a highly attractive but challenging target. Herein, we report the direct conversion of syngas into methyl acetate (MA) by relay catalysis. MA can be formed at a lower temperature (ca. 473 K) using Cu‐Zn‐Al oxide/H‐ZSM‐5 and zeolite mordenite (H‐MOR) catalysts separated by quartz wool (denoted as Cu‐Zn‐Al/H‐ZSM‐5|H‐MOR) and also at higher temperatures (603–643 K) without significant deactivation using spinel‐structured ZnAl2O4|H‐MOR. The selectivity of MA and acetic acid (AA) reaches 87 % at a CO conversion of 11 % at 643 K. Dimethyl ether (DME) is the key intermediate and the carbonylation of DME results in MA with high selectivity. We found that the relay catalysis using ZnAl2O4|H‐MOR|ZnAl2O4 gives ethanol as the major product, while ethylene is formed with a layer‐by‐layer ZnAl2O4|H‐MOR|ZnAl2O4|H‐MOR combination. Close proximity between ZnAl2O4 and H‐MOR increases ethylene selectivity to 65 %. [ABSTRACT FROM AUTHOR]

Abstract: Cellulose is a promising renewable and abundant resource for the production of high‐value chemicals, in particular, organic oxygenates, because of its high oxygen/carbon ratio. The sustainable production of hydroxycarboxylic acids and dicarboxylic acids, such as gluconic/glucaric acid, lactic acid, 2,5‐furandicarboxylic acid, adipic acid, and terephthalic acid, most of which are monomers of key polymers, have attracted much attention in recent years. The synthesis of these organic acids from cellulose generally involves several tandem reaction steps, and thus, multifunctional catalysts that can catalyze the selective activation of specific C−O or C−C bonds hold the key. This review highlights recent advances in the development of efficient catalytic systems and new strategies for the selective conversion of cellulose or its derived carbohydrates into functionalized organic acids. The reaction mechanism is discussed to offer deep insights into the regioselective cleavage of C−O or C−C bonds. [ABSTRACT FROM AUTHOR]

The direct synthesis of lower (C2 to C4) olefins, key building-block chemicals, from syngas (H2 /CO), which can be derived from various nonpetroleum carbon resources, is highly attractive, but the selectivity for lower olefins is low because of the limitation of the Anderson-Schulz-Flory distribution. We report that the coupling of methanol-synthesis and methanol-to-olefins reactions with a bifunctional catalyst can realize the direct conversion of syngas to lower olefins with exceptionally high selectivity. We demonstrate that the choice of two active components and the integration manner of the components are crucial to lower olefin selectivity. The combination of a Zr-Zn binary oxide, which alone shows higher selectivity for methanol and dimethyl ether even at 673 K, and SAPO-34 with decreased acidity offers around 70 % selectivity for C2-C4 olefins at about 10 % CO conversion. The micro- to nanoscale proximity of the components favors the lower olefin selectivity. [ABSTRACT FROM AUTHOR]

The aerobic oxidation of 5-hydroxymethylfurfural (HMF) into 2,5-furandicarboxylic acid (FDCA) is one of the most attractive reactions to establish biomass-based sustainable chemical processes. Supported Au and Pt catalysts have mainly been reported for this reaction, but excess amounts of base additives are generally required, which makes the process less green. Here, we demonstrate that Pt nanoparticles loaded on functionalized carbon nanotubes (CNTs) can catalyze the aerobic oxidation of HMF to FDCA in water without any base additives. Kinetic studies suggest a tandem reaction mechanism via 2,5-diformylfuran and 5-formylfurancarboxylic acid intermediates. It has been clarified that the oxygen-containing functional groups, in particular carbonyl/quinone and/or phenol groups, on CNT surfaces play crucial roles in FDCA formation. These functional groups could enhance the adsorption of HMF as well as the reaction intermediates from water and might facilitate hydrogen transfer. [ABSTRACT FROM AUTHOR]

Selectivity control is a challenging goal in Fischer-Tropsch (FT) synthesis. Hydrogenolysis is known to occur during FT synthesis, but its impact on product selectivity has been overlooked. Demonstrated herein is that effective control of hydrogenolysis by using mesoporous zeolite Y-supported cobalt nanoparticles can enhance the diesel fuel selectivity while keeping methane selectivity low. The sizes of the cobalt particles and mesopores are key factors which determine the selectivity both in FT synthesis and in hydrogenolysis of n-hexadecane, a model compound of heavier hydrocarbons. The diesel fuel selectivity in FT synthesis can reach 60 % with a CH4 selectivity of 5 % over a Na-type mesoporous Y-supported cobalt catalyst with medium mean sizes of 8.4 nm (Co particles) and 15 nm (mesopores). These findings offer a new strategy to tune the product selectivity and possible interpretations of the effect of cobalt particle size and the effect of support pore size in FT synthesis. [ABSTRACT FROM AUTHOR]

Bifunctional Fischer-Tropsch (FT) catalysts that couple uniform-sized Co nanoparticles for CO hydrogenation and mesoporous zeolites for hydrocracking/isomerization reactions were found to be promising for the direct production of gasoline-range (C5-11) hydrocarbons from syngas. The Brønsted acidity results in hydrocracking/isomerization of the heavier hydrocarbons formed on Co nanoparticles, while the mesoporosity contributes to suppressing the formation of lighter (C1-4) hydrocarbons. The selectivity for C5-11 hydrocarbons could reach about 70 % with a ratio of isoparaffins to n-paraffins of approximately 2.3 over this catalyst, and the former is markedly higher than the maximum value (ca. 45 %) expected from the Anderson-Schulz-Flory distribution. By using n-hexadecane as a model compound, it was clarified that both the acidity and mesoporosity play key roles in controlling the hydrocracking reactions and thus contribute to the improved product selectivity in FT synthesis. [ABSTRACT FROM AUTHOR]

Cover Feature: Upcycling Plastic Wastes into Value-Added Products by Heterogeneous Catalysis (ChemSusChem 14/2022) Arenes, carbon materials, heterogeneous catalysis, liquid hydrocarbons, plastic upcycling Keywords: arenes; carbon materials; heterogeneous catalysis; liquid hydrocarbons; plastic upcycling EN arenes carbon materials heterogeneous catalysis liquid hydrocarbons plastic upcycling 1 1 1 07/25/22 20220721 NES 220721 B The Cover Feature b shows the upcycling of various plastic wastes such as polyethylene (PE), polyethylene terephthalate (PET), and polylactic acid (PLA) into high-value chemicals, lubricants, fuels, and carbon materials. [Extracted from the article]

A hydrotalcite-supported gold catalyst has been found to be efficient for both oxidative and non-oxidative conversions of benzyl alcohol into benzaldehyde. In both cases, the reaction rates were dependent on the size of the Au particles, but the size dependence for the non-oxidative reaction was more pronounced. Our analyses on the intrinsic rates of different sites suggested that all of the atoms on the Au surfaces participated in the oxidative reaction, whereas the edge and corner Au atoms predominantly contributed to the non-oxidative reaction, and that the terrace atoms were at least two orders of magnitude less active than the edge or corner atoms. In both cases, the rate-determining step was CH bond cleavage. The presence of oxygen significantly enhanced the reaction rate. Herein, we propose that the non-oxidative reaction proceeds through a β-H elimination step by the low-coordination-number edge and corner Au atoms, whereas the active oxygen species, which are even generated on the terrace Au atoms, might assist CH bond cleavage under oxidative conditions. [ABSTRACT FROM AUTHOR]

Fischer-Tropsch synthesis is a key reaction in the utilization of non-petroleum carbon resources, such as methane (natural gas, shale gas, and biogas), coal, and biomass, for the sustainable production of clean liquid fuels from synthesis gas. Selectivity control is one of the biggest challenges in Fischer-Tropsch synthesis. This Minireview focuses on the development of new catalysts with controllable product selectivities. Recent attempts to increase the selectivity to C5+ hydrocarbons by preparing catalysts with well-defined active phases or with new supports or by optimizing the interaction between the promoter and the active phase are briefly highlighted. Advances in developing bifunctional catalysts capable of catalyzing both CO hydrogenation to heavier hydrocarbons and hydrocracking/isomerization of heavier hydrocarbons are critically reviewed. It is demonstrated that the control of the secondary hydrocracking reactions by using core-shell nanostructures or solid-acid materials, such as mesoporous zeolites and carbon nanotubes with acid functional groups, is an effective strategy to tune the product selectivity of Fischer-Tropsch synthesis. Very promising selectivities to gasoline- and diesel-range hydrocarbons have been attained over some bifunctional catalysts. [ABSTRACT FROM AUTHOR]

A fit catalyst for some aerobic exercise: A manganese oxide‐based octahedral molecular sieve, OMS‐2, could act as an efficient heterogeneous catalyst for the regioselective α‐cyanation of various tertiary amines, including trialkyl, benzylic, and N,N‐dialkylaniline derivatives using trimethylsilyl cyanide (TMSCN) as the cyano source and molecular oxygen as the terminal oxidant. [ABSTRACT FROM AUTHOR]

Cross‐dehydrogenative coupling of various terminal alkynes and monohydrosilanes efficiently proceeded in the presence of gold supported on OMS‐2 (Au/OMS‐2) using O2 as a terminal oxidant, affording the corresponding alkynylsilanes in moderate to high yields (see picture). The observed catalysis was truly heterogeneous, and the catalyst could be reused at least ten times without a significant loss of its high catalytic performance. [ABSTRACT FROM AUTHOR]

The size of the active phase is one of the most important factors in determining the catalytic behaviour of a heterogeneous catalyst. This Feature Articlefocuses on the size effects in two types of reactions, i.e., the metal nanoparticle-catalysed dehydrogenation of alcohols and the metal oxide nanocluster-catalysed selective oxidation of hydrocarbons (including the selective oxidation of methane and ethane and the epoxidation of propylene). For Pd or Au nanoparticle-catalysed oxidative or non-oxidative dehydrogenation of alcohols, the size of metal nanoparticles mainly controls the catalytic activity by affecting the activation of reactants (either alcohol or O2). The size of oxidic molybdenum species loaded on SBA-15 determines not only the activity but also the selectivity of oxygenates in the selective oxidation of ethane; highly dispersed molybdenum species are suitable for acetaldehyde formation, while molybdenum oxide nanoparticles exhibit higher formaldehyde selectivity. CuIIand FeIIIisolated on mesoporous silica are highly efficient for the selective oxidation of methane to formaldehyde, while the corresponding oxide clusters mainly catalyse the complete oxidation of methane. The lattice oxygen in iron or copper oxide clusters is responsible for the complete oxidation, while the isolated CuIor FeIIgenerated during the reaction can activate molecular oxygen forming active oxygen species for the selective oxidation of methane. Highly dispersed CuIand FeIIspecies also function for the epoxidation of propylene by O2and N2O, respectively. Alkali metal ions work as promoters for the epoxidation of propylene by enhancing the dispersion of copper or iron species and weakening the acidity. [ABSTRACT FROM AUTHOR]

Ru nanoparticles loaded on a Keggin-type polyoxometalate (Cs3PW12O40), which did not possess strong intrinsic acidity, efficiently catalysed the conversions of cellobiose and cellulose into sorbitol in water medium in H2at ≤433 K. The Brønsted acid sites generated in situfrom H2have been demonstrated to play a key role in the formation of sorbitol. [ABSTRACT FROM AUTHOR]

The Cover shows the promising utilization of functionalized carbon nanotubes (CNTs) for the transformation of biomass into building‐block chemicals. In their Full Paper, W. Deng, Y. Yang, Y. Wang, and co‐workers demonstrate that a functionalized CNT‐supported Pt catalyst is highly efficient and stable for the aerobic oxidation of 5‐hydroxymethylfurfural (HMF) into 2,5‐furandicarboxylic acid (FDCA), in water without any base additives. It has been clarified that the oxygen‐containing functional groups, in particular carbonyl/quinone and/or phenol groups, on CNT surfaces play crucial roles in FDCA formation. More details can be found in the Full Paper by Zhou et al. on page 2853 in Issue 18, 2015 (DOI: 10.1002/cctc.201500352). [ABSTRACT FROM AUTHOR]

Review: 188 refs. [ABSTRACT FROM AUTHOR]

Novel bifunctional Fischer ‐ Tropsch catalysts which couple uniform ‐ sized cobalt nanoparticles for CO hydrogenation and mesoporous H ‐ ZSM ‐ 5 for hydrocracking/isomerization, have been successfully developed for direct production of gasoline ‐ range hydrocarbons with excellent selectivity (70%). The mesoporous structure overcomes the diffusion limitation, significantly suppressing the formation of unfavorable lighter alkanes. The Co/H ‐ meso ‐ ZSM ‐ 5 is a promising new ‐ generation Fischer ‐ Tropsch catalyst. For more details, see the Full Paper by Y. Wang et al. on page 1928 ff. [ABSTRACT FROM AUTHOR]

Abstract: The formation of methyl acetate during the conversion of CH4 with N2O and CO over heterogeneous catalysts containing both rhodium and iron phosphate was studied. For two series of Rh-doped FePO4 catalysts prepared by different methods, the optimum atomic ratios of Rh/Fe for methyl acetate formation are 1:600–1:400. The Rh–FePO4 catalyst prepared from a mixed aqueous solution exhibits a higher rate and turnover frequency for methyl acetate formation than the Rh/FePO4 prepared by the impregnation method. Characterizations with XRD, diffuse-reflectance UV–vis, TEM, and H2-TPR suggest that Rh3+ ions are mainly incorporated into the lattice of FePO4 in the Rh–FePO4 prepared from the mixed aqueous solution, whereas Rh(III) species probably exist on the surface of FePO4 in the Rh/FePO4 prepared by impregnation. The support of Rh(III) species and FePO4 by MCM-41 by a co-impregnation method can drastically increase the rate and turnover frequency for methyl acetate formation, whereas a two-step impregnation method leads to catalysts without methyl acetate formation. The dual site containing Rh(III) species and FePO4 in close proximity is proposed to account for methyl acetate formation. A possible reaction mechanism has been proposed on the basis of kinetic investigations. [Copyright &y& Elsevier]

Review: 94 refs. [ABSTRACT FROM AUTHOR]

Nb2O5·xH2O nanosheets are hydrothermally synthesized from mixtures of NbCl5 dissolved in EtOH and aqueous NH3 solutions (autoclave, 513 K, 24 h). [ABSTRACT FROM AUTHOR]