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Single‐atom catalysts (SACs) have recently become highly attractive for selective hydrogenation reactions owing to their remarkably high selectivity. However, compared to their nanoparticle counterparts, atomically dispersed metal atoms in SACs often show inferior activity and are prone to aggregate under reaction conditions. Here, by theoretical calculations, we show that tuning the local electronic structures of metal anchor sites on g‐C3N4 by doping B atoms (BCN) with relatively lower electronegativity allows achieving zero‐valence Pd SACs with reinforced metal‐support orbital hybridizations for high stability and upshifted Pd 4d orbitals for high activity in H2 activation. The precise synthesis of Pd SACs on BCN supports with varied B contents substantiated the theoretical prediction. A zero‐valence Pd1/BCN SAC was achieved on a BCN support with a relatively low B content. It exhibited much higher stability in a H2 reducing environment, and more strikingly, a hydrogenation activity, approximately 10 and 34 times greater than those high‐valence Pd1/g‐C3N4 and Pd1/BCN with a high B content, respectively. [ABSTRACT FROM AUTHOR]

The CaO-supported Pt nanoparticle catalysts, herein referred to as the Pt/CaO-P catalysts, were synthesized for the first time to catalyze the selective hydrogenation of styrene oxide. All previously reported Pt- and Pd-based catalysts were prepared and evaluated under identical conditions, with 2-phenylethanol (2-PEA) being identified as the primary product in the selective hydrogenation of styrene oxide. The comparative analysis of the catalytic performance of Pt/CaO-P, Pt/CaO (unpurified), Pt/Ca(OH)2, and Pt/CaCO3 revealed that the purity of CaO is crucial for enhancing the selectivity towards 1-phenylethanol (1-PEA). Notably, the highest selectivity of 1-PEA over Pt/CaO-P reached up to 39%. Our SO-TPD, CO2-TPD and ex situ FT-IR results further indicated that strong basic sites can modify the adsorption site of SO over Pt nanoparticles, leading to the higher selectivity of 1-PEA. A proposed reaction mechanism for the ring opening of styrene oxide suggests that the breakage of conjugation between the benzene ring and the adjacent carbon cation by strong basic sites plays an important role. [ABSTRACT FROM AUTHOR]

The development of nonpyrolytic catalysts featuring precisely defined active sites represents an effective strategy for investigating the fundamental relationship between the catalytic activity of oxygen reduction reaction (ORR) catalysts and their local coordination environments. In this study, we have synthesized a series of model electrocatalysts with well‐defined CoN4 centers and nonplanar symmetric coordination structures. These catalysts were prepared by a sequential process involving the chelation of cobalt salts and 1,10‐phenanthroline‐based ligands with various substituent groups (phen(X), where X=OH, CH3, H, Br, Cl) onto covalent triazine frameworks (CTFs). By modulating the electron‐donating or electron‐withdrawing properties of the substituent groups on the phen‐based ligands, the electron density surrounding the CoN4 centers was effectively controlled. Our results demonstrated a direct correlation between the catalytic activity of the CoN4 centers and the electron‐donating ability of the substituent group on the phenanthroline ligands. Notably, the catalyst denoted as BCTF−Co‐phen(OH), featuring the electron‐donating OH group, exhibited the highest ORR catalytic activity. This custom‐crafted catalyst achieved a remarkable half‐wave potential of up to 0.80 V vs. RHE and an impressive turnover frequency (TOF) value of 47.4×10−3 Hz at 0.80 V vs. RHE in an alkaline environment. [ABSTRACT FROM AUTHOR]

Supported‐metal catalysts, pivotal for industrial applications, have their catalytic properties affected by metal‐support interactions (MSIs), which notably influence both their electronic and geometric characteristics. Therefore, understanding internal and external factors that influence MSIs is crucial for the rational design of catalysts. Our minireview focuses on the effects of the gas environment on the MSIs, particularly the morphological changes in metal nanoparticles, the migrating behavior of reducible supports (strong metal‐support interaction), and the compositional rearrangement of the catalysts (reactive metal‐support interaction). Future directions are suggested to elucidate the fundamental aspects of gas environment induced structural reconstruction of catalysts, including the quantitative analysis of dynamic behavior of both the surface and interface, atomic‐level insights into the structures of the metal, support, and interface under pertinent conditions through advanced in situ/operando characterization, and the in situ manipulation of structural reconstruction. [ABSTRACT FROM AUTHOR]

Industrial-use VOx-based catalysts usually have a higher active temperature window (> 250-300°C), which becomes a "bottleneck" for the practical application of PCDD/Fs catalytic degradation technology. In this work, VOx-FeOx/TiO 2 catalyst prepared via mechanochemically method was investigated for the catalytic removal of PCDD/Fs. The removal efficiency of 1,2-DCBz, pure PCDD/Fs gas generated in the lab, PCDD/Fs from actual flue gas, long-term were studied, and the degradation mechanism was explored using FTIR and TOFMS. The degradation efficiency of 1,2-DCBz and PCDD/Fs on VOx-FeOx/TiO 2 were higher than that of VOx/TiO 2 catalyst, and the optimal FeOx addition ratio was 3 wt.%. The characterization results show that the addition of FeOx can effectively improve the pore structure, surface acidity, and VOx dispersion of the catalyst, thus contributing to increasing the V5+ content and surface-active oxygen, which is conducive to the improvement of adsorption and redox performance of the catalyst. Under the actual MSWI (municipal solid waste incineration) flue gas, the PCDD/Fs removal efficiency over VTi-3Fe-MC maintained long-term stability, higher than 85% for 240 min. This result was not significantly reduced compared with the data obtained in the laboratory. According to the analysis results of intermediate products by FTIR and GC-TOFMS, it can be inferred that the epoxidation fracture of benzene ring is the rate-limiting step of dioxin catalytic degradation reaction. This work gives an in-depth view into the PCDD/Fs removal over VOx-FeOx/TiO 2 catalysts and could provide guidelines for the rational design of reliable catalysts for industrial applications. [Display omitted] [ABSTRACT FROM AUTHOR]

Tetracycline becomes a crucial measure for managing and treating communicable diseases in both human and animal sectors due to its beneficial antibacterial properties and cost-effectiveness. However, it is important not to trivialize the associated concerns of environmental contamination following the antibiotic's application. In this study, cobalt ferrate (CoFe2O4) nanoparticles were loaded into chitosan (CS), which can avoid the agglomeration problem caused by high surface energy and thus improve the catalytic performance of cobalt ferrate. And it can avoid the problem of secondary contamination caused by the massive leaching of metal ions. The resulting product was used as a catalyst to activate peroxymonosulfate (PMS) for the degradation of tetracycline (TC). To determine the potential effects on TC degradation, various factors such as PMS dosing, catalyst dosing, TC concentration, initial solution pH, temperature, and inorganic anions (Cl−, H2PO4− and HCO3−) were investigated. The CS/CoFe2O4/PMS system exhibited superior performance compared to the CoFe2O4-catalyzed PMS system alone, achieving a 92.75% TC removal within 120 min. The catalyst displayed high stability during the recycling process, with the efficiency observed after five uses remaining at a stable 73.1%, and only minor leaching of dissolved metal ions from the catalyst. This confirms the high stability of the catalyst. The activation mechanism study showed that there are free radical and non-free radical pathways in the reaction system to degrade TC together, and SO4•− and 1O2 are the primary reactive oxygen radicals involved in the reaction, allowing for effective treatment of contaminated water by TC. [ABSTRACT FROM AUTHOR]

Developing low‐cost and high‐efficient bifunctional catalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is greatly significant for water electrolysis. Here, Ni3N‐CeO2/NF heterostructure is synthesized on the nickel foam, and it exhibits excellent HER and OER performance. As a result, the water electrolyzer based on Ni3N‐CeO2/NF bifunctional catalyst only needs 1.515 V@10 mA cm−2, significantly better than that of Pt/C||IrO2 catalysts. In situ characterizations unveil that CeO2 plays completely different roles in HER and OER processes. In situ infrared spectroscopy and density functional theory calculations indicate that the introduction of CeO2 can optimizes the structure of interface water, and the synergistic effect of Ni3N and CeO2 improve the HER activity significantly, while the in situ Raman spectra reveal that CeO2 accelerates the reconstruction of OV (oxygen vacancy)‐rich NiOOH for boosting OER. This study clearly unlocks the different catalytic mechanisms of CeO2 for boosting the HER and OER activity of Ni3N for water splitting, which provides the useful guidance for designing the high‐performance bifunctional catalysts for water splitting. [ABSTRACT FROM AUTHOR]

Catalytic thermal hydrogenation of CO2 to CH4 is one of the promising decarbonization technologies, and Ru is considered to be the most active metal for low‐temperature CO2 methanation. In this work, a series of metal‐promoted Ru‐based catalysts were prepared by the impregnation–precipitation method. The catalyst composition, reduction temperature, reaction gas concentration, and reaction conditions were optimized. The reaction mechanism was investigated through CO‐DRIFTS experiments. It was found that the addition of Pt could promote the adsorption of CO on the surface of ruthenium‐based catalysts, which was beneficial to the methanation reaction. In addition, in situ DRIFTS experiments observed surface species of catalysts during the reaction, and it was concluded that bicarbonate was the intermediate species of the reaction. © 2023 Society of Chemical Industry and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Tuning the strong metal‐support interaction (SMSI) in metal catalysts is a promising strategy to improve their catalytic performance. In this article, we systematically investigated the influences of different alcohol/water mixtures on the evolution of the interfacial structure of Cu/ZnO catalysts in the reduction stage. A series of in situ characterization and theoretical simulation studies were performed to elucidate the various mechanisms of alcohol induced SMSI. It was found that when methanol/water is added to H2 during the reduction pretreatment, more oxygen vacancies are formed on the ZnO support, which facilitates the dissociation of H2O and the hydroxylation of ZnO species. Such promotion eventually favors the SMSI between Cu and ZnO and increases the catalytic activity for the methanol steam reforming reaction. In contrast, the addition of ethanol/water and 1‐propanol/water during reduction leads to a physical blockage of the catalyst by alcohol molecules, poisoning the active Cu sites and limiting the migration of ZnO species. [ABSTRACT FROM AUTHOR]

The development of non‐noble metal catalysts is crucial for hydrogen production. In this study, electrochemically reconfigurable Fe2O3@NiO‐x composite catalysts were synthesized within tens of seconds using a simple microwave deposition method. Interestingly, Fe2O3@NiO‐5 exhibited a high‐speed and deep surface reconstruction capability, greatly enhancing the hydrogen evolution reaction (HER) activity. DFT calculations also confirmed that the reconstruction process optimized the adsorption energy of H2O and H intermediate to promote HER kinetics. The optimized Fe2O3@NiO‐5 electrode only afforded an overpotential of 295 mV at 10 mA cm−2 and it steadily functioned for 25 h for HER in 1 M KOH. In addition, benefiting from the combination of Fe2O3 and NiO layer during the synthesis process, Fe2O3 and NiO converted into FeOOH and NiOOH, respectively, resulted in the excellent oxygen evolution reaction (OER) activity of Fe2O3@NiO‐5. The as‐prepared Fe2O3@NiO‐5 only required an overpotential of 186 mV at 10 mA cm−2 and exhibited excellent stability for up to 144 h. As a bifunctional catalyst, the Fe2O3@NiO‐5 electrode can deliver a current density of 20 mA cm−2 at a low voltage of 1.78 V with high durability for water splitting. This work can provide a new perspective for constructing advanced non‐noble metal electrode. [ABSTRACT FROM AUTHOR]

Fabrication of MOFs with missing linker defects has become a common means to improve catalytic performances. However, the stability of the defects deserves to be investigated first. In this work, we found that 3-phenylpropionaldehyde (3-PPA) could coordinate with the missing linker defects of UiO-66, which highlighted the instability of the missing linker defects. 3-PPA acted as a molecular patch for the modification of the Rh/UiO-66 catalyst, which repaired the open Zr6 sites and resulted in a remarkable improvement of aldehyde selectivity (from 50.0% to 89.6%) in 1-hexene hydroformylation. [ABSTRACT FROM AUTHOR]

Developing easily recyclable noble metal nanoparticle‐based heterogeneous catalysts is highly desirable for the practical applications. Herein, a millimeter‐sized hierarchical porous titanosilicate (HPTS) was prepared by the multi‐template method. Various characterization results reveal that HPTS combines the structural advantages of monolith materials and nanomaterials. HPTS is used as an advanced support to construct the Ag/HPTS catalysts via the Ag+ in situ reduction on its pore wall. Ag/HPTS shows high catalytic activity for 4‐nitrophenol (4‐NP) reduction with the TOF values of 3.91 min−1, which can be attributed to the ultrafine Ag NPs (2.04 nm) and the unique structure of HPTS. The 3D pass‐through macroporous channels facilitate mass transfer. The mesopores with ultra‐short channel remarkably enhance the accessibility of the active sites. The abundant mesopores and micropores effectively confine the Ag NPs size. Moreover, Ag/HPTS demonstrated good stability and recyclability. [ABSTRACT FROM AUTHOR]

Catalytic hydrogenation of sulfur-containing substrates is an important and challenging reaction in the industry. In this work, carbon shell covered Pd catalysts were prepared by CVD process using acetylene as the precursor. During the process of CVD, the physical properties and the carbon content of the catalysts are closely related to the deposition temperature. The as-prepared C@Pd/TiO2 catalysts showed the higher conversion (nearly 100%) and stability for the hydrogenation of 4-nitrothioanisole than the Pd/TiO2 catalyst (45.5%). The excellent catalytic performance of C@Pd/TiO2 catalyst can be attributed to the appropriate amount of carbon shell covering the surface of the catalyst. Compared with Pd/TiO2 catalyst, the C@Pd/TiO2 catalysts has only a tiny amount of sulfur-containing substrates deposited on the catalysts surface after three recycles by XPS analysis, which illustrates the reason for sulfur-resistance of the carbon shell covered Pd-based catalyst. [ABSTRACT FROM AUTHOR]

[Display omitted] • Prepared Cu-In bimetallic catalysts exhibit greatly enhanced CO 2 RR performance compared to the In catalyst. • The Cu1+ species dope into the In(OH) 3 crystal lattice for the fresh Cu-In catalysts, while small CuO nanoparticles form on the catalyst surface with high Cu contents. • The dynamic structure evolution phenomenon exists during CO 2 RR, and the Cu0-In(OH) 3 active interface is evolved. • The adsorption of CO 2 is greatly facilitated after adding Cu compared to the In catalyst. • RDS for formate production is changed on Cu0-In(OH) 3 active sites. In-based bimetallic catalysts show great potential to reduce CO 2 electrochemically. However, the nature of active sites and reaction mechanisms are not fully understood. This study systematically investigates the role of Cu in the Cu-In bimetallic catalysts during the reaction. The partial current densities of formate and CO show a linear correlation with increased Cu content. CuIn3 shows a total current density of 6.40 mA cm−2 and the highest Faradic efficiency for C1 products of 99.3% at −0.7 V vs RHE. A series of characterizations reveal that the Cu1+ species dope into the In(OH) 3 lattice for the Cu-In catalysts, while small CuO nanoparticles also form on the surface of catalyst with high Cu contents. The CuO and Cu1+ species are reduced to metallic Cu0, leading to the formation of the Cu0-In(OH) 3 interfacial sites. Adding Cu is found to facilitate the adsorption of CO 2 and shift the rate-determining step for formate production. [ABSTRACT FROM AUTHOR]

Well dispersible and stable single atom catalysts (SACs) with hydrophilic features are highly desirable for selective hydrogenation reactions in hydrophilic solvents towards important chemicals and pharmaceutical intermediates. A general strategy is reported for the fabrication of hydrophilic SACs by cation‐exchange approach. The cation‐exchange between metal ions (M = Ni, Fe, Co, Cu) and Na+ ions introduced in the skeleton of metal oxide (TiO2 or ZrO2) nanoshells plays the key role in forming M1/TiO2 and M1/ZrO2 SACs, which efficiently prevents the aggregation of the exchanged metal ions. The as‐obtained SACs are highly dispersible and stable in hydrophilic solvents including alcohol and water, which greatly facilitates the catalysis reaction in alcohol. The Ni1/TiO2 SACs have been successfully utilized as catalysts for the selective C=C hydrogenation of cinnamaldehyde to produce phenylpropanal with 98% conversion, over 90% selectivity, good recyclability, and a turnover frequency (TOF) of 102 h−1, overwhelming most reported catalysts including noble metal catalysts. [ABSTRACT FROM AUTHOR]

Recent advances in supported nickel catalysts for the water‐gas shift (WGS) reaction are reviewed, focusing on the structure‐mechanism relationships. The WGS reaction can proceed via the redox, carboxyl, and formate pathways over the supported nickel catalysts. However, a discrepancy exists between the mechanism‐level understanding and catalyst design principles in literature. In this review, we summarized the mechanism‐structure relationship of nickel‐based catalysts, emphasizing the effects of the formation of alloy, modification of the support or addition of alkali metal promoters on the CO adsorption and the H2O dissociation in the process of WGS reaction. Future research is suggested to systematically investigate the reaction mechanism & kinetics for different catalyst structures. In addition, the manipulation of strong metal‐support interactions and the development of new types of supports are prospective directions. [ABSTRACT FROM AUTHOR]

BACKGROUND: The development of efficient synthetic pathways for bio‐based chemicals is beneficial to sustainable development of the chemical industry. However, directional production of phenolic chemicals using lignocellulose remains a challenging issue, because the reaction paths as well as intermediates in the catalytic transformation of lignocellulose are often complicated. RESULTS: Bio‐based cresol can be selectively prepared from lignocellulose biomass. This steerable transformation has been achieved by lignocellulose catalytic pyrolysis to aromatic intermediates over a magnetic oxide‐modified zeolite catalyst (Fe3O4@HZSM‐5) and intermediate hydroxylation to cresol over a metal–organic framework catalyst (Cu‐MOF). Based on the analysis of intermediates and on catalyst characterization, the corresponding reaction pathways are put forward. Using the Cu‐MOF catalyst, the highest selectivity of cresol (81.5%) and the highest conversion (76.8%) were gained at 40 °C in 4 h. CONCLUSIONS: The work presented proves that an important phenolic chemical (cresol) can be selectively prepared from lignocellulose raw materials. The Cu‐MOF catalyst shows superior performance and good reusability in the bio‐cresol synthesis. Reactive oxygen species take a prominent role in the cresol synthesis. © 2022 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

Exploring active catalyst components is very important to develop high-performance and highly stable ORR electrocatalysts to replace costly Pt-based catalysts, though it remains an ongoing challenge. In this paper, three ORR catalysts with different active components were obtained by calcination of different proportions of mixed precursors simply and delicately. Among them, precursor 1 (bimetallic polymer Fe/Zn-ZIFs@ZnCO3) played the role of a self-sacrificing template, while precursor 2 (an N, P-co-doped polymer) played the role of a volatile atmosphere. Precursor 2 also embedded N and P heteroatoms into the carbon framework during high-temperature volatilization, which resulted in subtle changes in the active catalyst components. Finally, a hybrid of metal Fe and α-Fe2O3 nanoparticles embedded in N, P-codoped carbon nanotubes with many separated gullies (named α-Fe2O3/Fe@NPC) exhibited excellent ORR catalytic activity in an alkaline solution as compared to commercial Pt/C. This work provides a new strategy for designing controllable active components using volatile precursors. [ABSTRACT FROM AUTHOR]

The development of efficient synthetic pathways for bio-chemicals is beneficial to sustainable development of chemical industry. The purpose of this work is to prove that p-tolylaldehyde, an important chemical, can be selectively produced from lignocellulose. This novel transformation has been achieved by the catalytic pyrolysis of lignocellulose to p-xylene intermediate over the magnetic zeolite catalyst of Fe3O4@SiO2@HZSM-5 and the selective catalytic oxidation of the aromatic intermediate to p-tolylaldehyde over the magnetic catalyst of Cr(OH)3@Fe3O4-V. The screening and characterization of catalysts, the reaction condition optimization as well as the catalyst's reusability were studied. The highest p-tolylaldehyde yield of 51.0% was achieved using the Cr(OH)3@Fe3O4-V catalyst. According to the catalyst characterizations and the analysis of the reaction intermediates, the reaction pathways were proposed. Directional synthesis of bio-based p-tolylaldehyde, a bulk high value chemical, was achieved by coupling catalytic pyrolysis of lignocellulose biomass to p-xylene intermediate over the magnetic zeolite catalyst of Fe3O4@SiO2@HZSM5 and the catalytic oxidation of aromatic intermediate over the magnetic Cr(OH)3@Fe3O4 catalyst. [ABSTRACT FROM AUTHOR]

A series of catalysts containing Pt or Pd nanoparticles (NPs) jointly regulated by cytidine (Cs) and polyvinylpyrrolidone (PVP) have been prepared for selective hydrogenation of cinnamaldehyde (CAL). The Pt/Pd NPs were supported on carbon nanotubes (CNTs) with different structures for promoting catalytic activity and tuning product selectivity. The synergistic effect of Cs and PVP on Pt/Pd surface promotes hydrogenation activity. The synergy between Pd NPs and multi‐walled CNTs with the diameter of <8 nm greatly promoted the hydrogenation of C=C bond in CAL. The synergy between Pt NPs and single‐walled CNTs with the diameter of <2 nm effectively enhanced the hydrogenation of C=O bond in CAL. These synergistic effects are attributed to the suitable size and exposed (111) facets of metal NPs, the transfer of electrons and the interaction between metal and support. [ABSTRACT FROM AUTHOR]

Heterogeneous macromolecule catalysts have been known as efficient electrocatalysts for CO2 reduction reaction, however, manipulating the activity of heterogeneous molecules via controllable metal electronic structure is still challenging. Herein, different CO2 activated 3D, robust, nitrogen‐doped hollow carbon spheres are synthesized to anchor cobalt phthalocyanine as molecularly dispersed electrocatalysts, where the electron‐withdrawing coeffect of carbon defects and heteroatom N is responsible for tuning the electronic structure of metal center. The optimal electrocatalyst reveals high CO faradaic efficiency (FECO) of 95.68%, turnover frequency of 13.80 s−1, and current density of 16.49 mA cm−2 at an overpotential of 760 mV. The control experiment and DFT calculations unveil that the significant activity is mainly ascribed to the optimal electron‐withdrawing coeffect of carbon defects and pyrrolic N, which reduce the electron density of Co center to facilitate CO2 activated to form *COOH intermediate on Co(I) active sites during electrocatalysis. The 2p‐charge loss of Co is summarized as an activity descriptor, which steers the current density and production rate toward CO. Furthermore, the design strategy can universally fabricate the hybrid MPc catalyst with transitional metal (Ni, Fe) site while a rechargeable Zn–CO2 battery is devised to deliver a maximal power density of 1.02 mW cm−2. [ABSTRACT FROM AUTHOR]

A series of Rh-based catalysts with various crystalline phases (p25, anatase, and rutile) were prepared via the incipient-wetness impregnation method. It was found that these catalysts had different metal–support interactions. Hence, 1%Rh/p, 1%Rh/r, and 1%Rh/a exhibited methane, CO, and methanol selectivity, respectively. [ABSTRACT FROM AUTHOR]

The high toxicity and low volatility of PCDD/Fs prevent detailed study of their catalytic degradation removal characteristics. In this study, 1,2-dichlorobenzene (1,2-DCBz) was initially used as a model to investigate the catalytic characteristics of various vanadium-based catalysts prepared by different methods. Then, the optimized catalyst was used for catalytic degradation of real PCDD/Fs at low temperatures based on a self-made stable source. The VOx/TiO2 catalysts synthesized by the mechanochemical method (VTi-MC2) had a higher 1,2-DCBz removal efficiency (>85%) and stability (> 420 min) at low temperatures (< 200 °C) compared to VTi-SG (sol-gol method) and VTi-WI (wetness impregnation method). The physicochemical properties of catalysts were studied using comprehensive characterization. It was found that the VTi-MC2 has better VOx species distribution and possesses the highest V5+ species and surface adsorbed oxygen content, which are the key factors that contributed to the higher removal efficiency. Accordingly, the mechanochemical method can be used to control the physicochemical properties of catalysts by adjusting the milling parameters. The optimum ball milling time is 2 h and a suitable precursor is NH4VO3 for VOx/TiO2. Moreover, the removal efficiency and catalytic degradation efficiency of PCDD/Fs in gas phase catalyzed by VTi-MC2 were 97% and 50% respectively, within a range of temperatures below 200 °C, which are both higher than those reported research. In general, the mechanochemical strategy employed in this study provides a means for seeking more efficient catalysts used for low-temperature degradation of various trace organic pollutants. [ABSTRACT FROM AUTHOR]

This work aims to demonstrate that cresol, an important high added value chemical in petrochemical industry, can be directionally produced using cellulose. This novel controllable transformation process was achieved by selective catalytic pyrolysis of cellulose and catalytic oxidation. The zinc oxide-doped strong acidic zeolite catalyst promoted the formation of toluene intermediate in the catalytic pyrolysis of cellulose. The CuCr2O4@MCM-41 catalyst exhibited high activity and good reusability in the catalytic oxidation process. The highest cresol selectivity of 87.5% with conversion of 83.0% was obtained using the CuCr2O4@MCM-41 catalyst and hydrogen peroxide as a green oxidant under the optimized reaction conditions (60 °C, 4 h). Based on the study of the model compounds and catalyst characterizations, the reaction pathways and possible reaction mechanism for the catalytic transformation of cellulose to bio-based cresol have been proposed. [ABSTRACT FROM AUTHOR]

In the present work, we demonstrate that the mechanism and kinetics of CO2 activation, as the first step of its hydrogenation, over supported nickel catalysts is particle size sensitive owing to the distinct H2 dissociation ability over nickel particles with various sizes. Large nickel nanoparticles facilitate H2 dissociation, enabling CO2 activation via a kinetically favored redox mechanism compared to small nickel nanoparticles that activate CO2 via the formate mechanism. The elucidation of the dependency of the catalytic reaction pathway on particle size will guide the rational design of supported nickel catalysts for selective CO2 hydrogenation. This work demonstrated in the CO2 hydrogenation reaction, CO2 is activated through different mechanisms due to different H2 dissociation capabilities over supported Ni catalysts with different particle sizes, which provides a convincing experimental explanation for the structural sensitivity of nickel‐based catalysts. [ABSTRACT FROM AUTHOR]

Two types of SiO2 with different microporosities were evaluated as supports for the Ni/SiO2 catalysts. The CO2 methanation performance of the catalysts was evaluated, and the structure‐activity relationship was elucidated with thorough characterizations. For the Ni/SiO2 catalyst with plenty of micropores, both ultrasmall Ni nanoclusters and larger Ni nanoparticles are present. In contrast, the one with fewer micropores only contains large Ni nanoparticles. During the CO2 methanation reaction, CO2 can be activated to CO on small Ni nanoclusters and further converted to CH4 on larger Ni nanoparticles. Such a tandem catalysis behavior greatly improves the CO2 methanation activity. The CH4 yield reaches 33.5 μmol·g–1·s–1 at 450 °C under 0.1 MPa with a feed H2/CO2 mol ratio of 4:1 and a space velocity of 30 L·h–1·g–1. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The powder shape of a catalyst limits its practical applications in advanced oxidation processes. Herein, we used carbon fiber cloth (CFC) as a flexible matrix and introduced a carbon layer on its surface (c-CFC). CeVO 4 nanoparticles were synthesized on the c-CFC surface using a chemical deposition method, successfully fabricating a CeVO 4 /c-CFC carbon fiber-supported membrane catalyst for peroxymonosulfate (PMS) activation. The results indicate that CeVO 4 /c-CFC (2 × 2 cm2) has excellent reusability and can efficiently remove 97% of tetracycline (TC) within 15 min. The interaction between CeVO 4 and CFC provides abundant active sites, and promotes electron transfer. Furthermore, the carbon layer modification enhances the interfacial contact and electrochemical performance. In addition, hydroxyl radicals, sulfate radicals, and singlet oxygen species are also involved in TC degradation. Finally, the unique membrane shape endows the catalyst with easy recyclability and low environmental toxicity in practical applications. • A filter membrane-shaped CeVO 4 /c-CFC catalyst exhibits recyclable properties. • CFC, serving as a support, promotes the PMS activation of the catalyst. • The carbon modification of CFC enhances interfacial contact and charge transfer. • Abundant surface active sites and fast electron transfer are key factors. • •OH, SO 4 •−, and 1O 2 species are involved in the degradation of TC. [ABSTRACT FROM AUTHOR]

Herein, we report a copper(I)-catalyzed ring expansion reaction of isoxazoles with 4-diazoisoquinolin-3-ones, furnishing a series of densely substituted novel spiro[isoquinoline-4,2'- [1,3]oxazin]-3-ones in good to excellent yields. Broad substrate scope, readily available starting materials, cheap catalyst, mild reaction conditions and scalability are the prominent features of this methodology. [Display omitted] [ABSTRACT FROM AUTHOR]

The rape straw derived biochar supported-Co 3 O 4 catalyst was prepared for tetracycline hydrochloride (TC) degradation via peroxymonosulfate activation. [Display omitted] • The 20 wt% Co 3 O 4 /BC showed the best performance of activating PMS to degrade TC. • DFT calculations revealed the formation of BIEF pointing from BC to Co 3 O 4. • The BIEF driven catalytic degradation mechanism was proposed. • Both radical and non-radical processes contributed to the degradation of TC. The strong electronic interaction between heterogeneous composite catalysts facilitates the charge separation and transfer, which is favorable for the enhancement of catalytic performance. Herein, the rape straw derived biochar (BC) supported ultrafine Co 3 O 4 composites were synthesized for tetracycline hydrochloride (TC) degradation via activating peroxymonosulfate (PMS), and the built-in electric field (BIEF) driven catalytic degradation mechanism was proposed. The results indicated that 20 wt% Co 3 O 4 /BC catalyst could achieve 90% degradation efficiency of TC within 20 min, and demonstrated that BC not only served as a support to significantly inhibit the agglomeration of Co 3 O 4 nanoparticles and improve the stability of catalyst, but also behaved as an activator of PMS to participate in the catalytic degradation reaction. Both radical pathway (SO 4 · - , · OH and O 2 · -) and non-radical process ( 1 O 2 and direct electron transfer) were involved in the Co 3 O 4 /BC/PMS system, and the role of the latter is more prominent, in which Co2+/Co3+ redox cycle and C = O groups on the BC were the possible active sites. Furthermore, the density functional theory (DFT) calculations revealed that a BIEF pointing from BC to Co 3 O 4 at the interface was formed, which could act as the internal driving force for electron transfer to accelerate the redox cycle of Co2+/Co3+ and induce the direct electron transfer, and thus resulting in the better degradation of TC. This work not only offered a mechanistic insight into synergistic effects of composite catalyst in PMS activation, but also provided a win–win strategy of realizing the resource utilization of agricultural waste and environmental remediation simultaneously. [ABSTRACT FROM AUTHOR]

• Pd/HY is effectively promoted by doping millesimal phosphorus. • Support acidity, Pd dispersion and metal-support interaction are finely tuned. • Deep hydrogenation saturation of naphthalene in high yield is achieved. • Aggregation and leaching of Pd nanoparticles are inhibited for enhanced stability. Deep hydrogenation saturation of polycyclic aromatic hydrocarbons is of great importance for oil upgrading and chemical production. Pd/HY is an active catalyst for hydrogenation, but its acid property and metal-support interaction should be further tailored for selective deep hydrogenation saturation. In this paper, trace phosphorus in the order of one thousandth were doped into Pd/HY using a facile wet impregnation method. The influences of phosphorus doping on the physicochemical properties and catalytic performance of Pd/HY were systematically studied. Surface acidity of HY support, dispersion and electric state of Pd nanoparticles, and metal-support interaction were finely tuned by changing the doping amount of phosphorus. On the catalyst doped with 0.09 wt% phosphorus, the side reaction of hydrocracking was suppressed and deep hydrogenation saturation of naphthalene was greatly promoted for achieving a high yield of decalin. Meanwhile, doping millesimal phosphorus greatly enhanced the stability of the catalyst due to efficient inhibition of aggregation and leaching of active Pd nanoparticles in the harsh reaction environment and severe recycling process. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Tuning the location of Pd on HY by a dual-solvent strategy. • Structure transformation of Pd(OAc) 2 on HY via evaporation-induced aggregation. • Pd metal is in the electron-deficient state on Pd/HY. • Pd/HY catalysts with superior performance of deep hydrogenation saturation. Tuning the location of metal on the support is of great importance for catalyst performance optimization, which is hardly realized by the traditional impregnation method. Herein, a dual-solvent method using dichloromethane and water has been developed for the preparation of Pd/HY catalysts via evaporation-induced aggregation of Pd(OAc) 2. The state and location of Pd nanoparticles on HY can be effectively tuned by the water content in the dual-solvent system. Due to the filling of partial micropore channels by certain amount of water, hydrophobic Pd(OAc) 2 is selectively deposited on the un-occupied surface of HY, which is verified by the changes in textural and acid properties of the Pd/HY catalysts. FT-IR spectra illustrate the reconstruction of tridimensional Pd 3 (CH 3 COO) 6 trimer in solution to the planar bidentate Pd(II) acetate species on HY surface, which guarantees the stable loading of active Pd nanoparticles on HY. Pd nanoparticles selectively loaded around the junctions of micropores and mesopores of HY zeolite by moderate amount of water have been demonstrated to be highly active for the deep hydrogenation saturation of naphthalene. Due to the selective locating of Pd nanoparticles in the properly open space of HY, the B acid sites are well maintained and efficiently utilized for the enhanced anchoring of Pd nanoparticles and facilitated diffusion of the reactants. Therefore, the optimum Pd/HY catalyst possesses highly dispersed and electron-deficient Pd nanoparticles, and exhibited superior performance of hydrogenation saturation. The dual-solvent strategy can be applied to other zeolite systems to selectively loading of Pd nanoparticles for various catalytic applications. [ABSTRACT FROM AUTHOR]

The synergistic catalytic degradation of metal carbon-based composites is a feasible strategy to improve the efficiency of advanced oxidation processes (AOPs) by means of green chemistry. In this work, Fe 3 S 4 nanoparticles were anchored on the surface of peanut shell biochar to prepare magnetic Fe 3 S 4 /biochar (Fe 3 S 4 /BC) composites, which were applied to activate peroxymonosulfate (PMS) to degrade 2,4,6-trichlorophenol (2,4,6-TCP). The addition of biochar not only reduced the aggregation of Fe 3 S 4 nanoparticles, but also accelerated the electron transfer rate, and the constructed C-O-Fe bridges accelerated the regeneration of Fe(Ⅱ), which made Fe 3 S 4 /BC have better catalytic performance than pure Fe 3 S 4 even though the use of metal sulfides was reduced. Fe on the surface of Fe 3 S 4 /BC was the catalytic reaction center. The dominant role of sulfate radical (SO 4 ·-) and hydroxyl radical (HO·) on the degradation of 2,4,6-TCP was verified by electron paramagnetic resonance (EPR) and free radical quenching experiments. The mechanism of C-O-Fe bridges was verified by density functional theory (DFT) calculation. The mechanism of PMS activation by Fe 3 S 4 /BC was elucidated by electrochemical impedance spectroscopy (EIS) and X-ray photoelectron spectroscopy (XPS). Based on the detection results of intermediate products, the possible degradation pathways to 2,4,6-TCP were proposed. This work provides new insights into the synergistic catalytic mechanism of metal carbon-based sulfides and promotes the development of environmentally friendly and efficient metal carbon-based catalysts. [Display omitted] • The Fe 3 S 4 /BC exhibited superior catalytic performance to the pure Fe 3 S 4. • BC improved dispersion of Fe 3 S 4 nanoparticles and accelerated electron transfer. • Fe3+/Fe2+ cycle was facilitated by reducing sulphur species and C-O-Fe bridges. • The Fe 3 S 4 /BC/PMS system is suitable for a wide pH range. • Both SO 4 ·- and HO· were responsible for 2,4,6-TCP degradation, especially SO 4 ·-. [ABSTRACT FROM AUTHOR]

Novel Fe supported core-shell catalysts, composite materials of metal-organic frameworks (UiO-66) and zeolite (Silicalite-1), were designed for efficient catalytic wet peroxide oxidation of phenolic wastewater. The core-shell materials using UiO-66 and Silicalite-1 as the core layer or shell layer were prepared by secondary synthesis method and characterized by SEM, TEM, EDS mapping, XRD and FT-IR. The Fe species (5 wt%) supported core-shell catalysts were prepared by incipient wetness impregnation method. Characterization results certificated the successful preparation of core-shell catalysts, namely, Fe-UiO-66/Silicalite-1 (UiO-66 as the core material) and Fe-Silicalite-1/UiO-66 (Silicalite-1 as the core material). Meanwhile, the Fe supported core-shell catalysts exhibited good catalytic activity with complete phenol degradation and TOC conversions of 66% and 69% over the Fe-UiO-66(25)/Silicalite-1 and Fe-Silicalite-1(25)/UiO-66, respectively, without poisonous by-products detected in the treated wastewater, which further proved the green characteristic of the catalysts. The Fe leaching concentration in the treated solution over the Fe-UiO-66/Silicalite-1 and Fe-Silicalite-1/UiO-66 catalyst is 0.235 ppm and 0.352 ppm which certificated the enhanced stability of the MOFs Fenton catalysts by preparing the supported core-shell catalysts. [Display omitted] • Core-shell Fe-UiO-66/Silicalite-1 catalysts were successfully prepared. • The catalysts exhibited outstanding activity for the CWPO of phenolic wastewater. • The H 2 O 2 decomposition rate was controllable by adjusting the core materials. • No poisonous intermediates were detected in the CWPO over the core-shell catalysts. [ABSTRACT FROM AUTHOR]

[Display omitted] Lignin upgrading to various functional products is promising to realize high-value utilization of low-cost and renewable biomass waste, but is still in its infancy. Herein, using industry waste lignosulfonate as the biomass-based carbon source and urea as the dopant, we constructed a heteroatom-doped porous carbon nanosheet structure by a simple NaCl template-assisted pyrolytic strategy. Through the synergistic effect of the NaCl template and urea, the optimized lignin-derived porous carbon catalyst with high content of active nitrogen species and large specific surface area can be obtained. As a result, the fabricated catalysts exhibited excellent electrocatalytic oxygen reduction activity, as well as good methanol tolerance and stability, comparable to that of commercial Pt/C. Moreover, rechargeable Zn-air batteries assembled with this electrocatalyst have a peak power density of up to 150 mW cm-2 and prominent long-term cycling stability. This study offers an inexpensive and efficient way for the massive production of highly active metal-free catalysts from the plentiful, inexpensive and environmentally friendly lignin, offering a good direction for biomass waste recycling and utilization. [ABSTRACT FROM AUTHOR]

[Display omitted] • A new method to synthesize PdNi, PdCu, and PdFe nanoalloy was proposed. • The Pd based nanoalloy was prepared through a carbon promoting method. • Carbon doping significantly accelerates the displacement rate of nickel. • This catalyst exhibited excellent catalytic performance for pollution treatment. • This catalyst showed high stability in the flow test. PdNi nanoalloy catalysts were prepared by a carbon-promoted galvanic replacement method. Characterizations and control experiments show the increased replacement rate of metal Ni with Pd2+ ion can be attributed to the higher electrode potential and smaller crystalline sizes caused by carbon doping. Introduction of carbon (C) into Ni particles not only accelerates the formation process of PdNi nanoalloys, but also enables C atoms to successfully enter the lattice interstices of PdNi nanoalloys. C regulates the surface electronic properties of PdNi nanoalloys by the electron transfer between different elements and improves their activity. The PdNi@C-650 exhibits extraordinary activity and long-term stability for hydrogenation reduction of hexavalent chromium (Cr (VI)) and hydrodechlorination of chlorophenols in comparison with PdNi/CNTs (carbon nanotubes) and commercial Pd/C. Density functional theory calculations together with investigations of mechanism reveal that the high electron-deficient PdNi nanoalloys from the redistribution of electron between Ni, Pd and C of the PdNi@C-650 promote the surface adsorption of substrate molecules and H 2 , which accordingly enhances the hydrogenation activity. This study brings a new method for the design and preparation of high active noble metal nanoalloy. [ABSTRACT FROM AUTHOR]

[Display omitted] • Metal phosphides@carbon was synthesized using a new polymeric phosphorus source. • Different metal phosphides@carbon catalyst can be synthesized by this method. • This catalyst exhibited excellent catalytic performance for selective hydrogenation. • This catalyst showed high anti-sulfur poisoning and anti-acid corrosion capability. A universal strategy to synthesize metal phosphides (MPs, M = Ni, Co, Cu, Fe, Pd, Pt, Ru) nanoparticles encapsulated in 2D defect-rich graphitic carbon shell (MPs@C-PPS) using P- and C-rich polymeric phosphide (PPS) as the precursor was brought out. Characterization results demonstrate that the thickness of the carbon shell on different MPs nanoparticles ranges from 1 to 7 nm, which can be adjusted by changing the Ni/P molar ratio. Some cracks and irregular defects are observed in carbon layers, which can selectively permeate small hydrogen molecules and block the passage of larger organic molecules. In catalytic performance test, the as-synthesized Ni 2 P@C-PPS exhibited excellent selectivity in alkynes semihydrogenation and high anti-sulfur poisoning and anti-acid corrosion capability in hydrogenation reactions. Mechanism exploration indicates that selective permeability of the carbon shell is the key to improving catalyst robustness. [ABSTRACT FROM AUTHOR]

[Display omitted] • The introduction of Zr onto the Cu/ZnO catalyst (Zr-modified Cu/ZnO) exhibits higher activity of MSR than of the Cu/ZnO catalyst. • Surface structure of the catalyst strongly depends on the content of Zr. • Moderate Zr increases Cu dispersion and forms ZnZrO x solid solution, leading to the formation of Cu-ZnZrO x and Cu-ZnO interfacial sites. • Excess Zr results in an increase both Cu nanoparticles size and Cu-ZrO 2 interfacial sites. • The Cu-ZnO and Cu-ZnZrO x interfacial sites is regarded as key active sites, which facilitates the methoxy dehydrogenation. Acknowledged as an ideal method for in situ hydrogen generation, methanol steam reforming (MSR) requires high-performance catalysts to enhance production efficiency. Herein, we prepared a series of Zr-modified Cu-based catalysts by a coprecipitation method and conducted a systematic analysis of the impacts of structural variations on MSR performance. Extensive characterization reveals a strong dependence of the catalyst's surface structure on Zr content. Introducing a moderate amount of Zr to the Cu/ZnO catalysts forms ZnZrO x solid solution and increases Cu dispersion, forming more Cu-ZnZrO x and Cu-ZnO interfacial sites with higher H 2 production rate. Further increases in Zr content enlarge Cu nanoparticles and multiply Cu-ZrO 2 interfacial sites. The optimal catalyst with a Zn/Zr molar ratio of 5, with the richest Cu-ZnO/Cu-ZnZrO x interfacial sites, achieves the highest H 2 production rate of 117.4 mmol H 2 g cat -1 h -1 at 200 °C, which is 1.3 times and 6.8 times higher than those of Cu/ZnO and Cu/ZrO 2 , respectively. [ABSTRACT FROM AUTHOR]

• The Fe(OH) 3 /Ni-NiO heterojunction was successfully prepared. • The Fe(OH) 3 /Ni-NiO as bifunctional catalysts showed high HER and OER activities. • The heterogeneous interface between Ni, NiO and Fe(OH) 3 promoted the HER process. Exploring economic-efficient bifunctional catalysts is critical for the production of green hydrogen through water splitting. Herein, we fabricate a novel hybrid catalyst with three-phase heterojunction (Fe(OH) 3 /Ni-NiO) via a simple electrodeposition and chemical precipitation method. Benefiting from the desirable amorphous-crystal interfaces, the electronic structure of Ni, NiO and Fe(OH) 3 is regulated, which will optimize the adsorption of H intermediates (H*) and also reduce the kinetic barrier for the hydrogen evolution reaction (HER). The optimal Fe(OH) 3 –3/Ni-NiO/CC shows superior bifunctional activity with low overpotentials of 66 mV for HER and 220 mV for OER at 10 mA cm−2 in alkaline solution, respectively, as well as remarkable durability over a period of 40 h. Besides, Fe(OH) 3 –3/Ni-NiO/CC requires 1.52 and 1.72 V to deliver 10 and 100 mA cm−2 and shows no obvious increase in current within 40 h toward overall water splitting. Experimental and theoretical results show that the HER process is promoted by the synergistic effect of electronic redistribution between Ni, NiO and Fe(OH) 3 due to the construction of three phase crystalline-amorphous heterogeneous interface. Meanwhile, Fe(OH) 3 and NiO appeared reconstruction, transforming into FeOOH and NiOOH during OER process, respectively. This work offers a simple synthesis method for designing bifunctional catalysts for water splitting. We fabricate a novel hybrid catalyst with three-phase heterojunction (Fe(OH) 3 /Ni-NiO) via a simple electrodeposition and chemical precipitation method. The optimal Fe(OH) 3 -3/Ni-NiO/CC shows superior bifunctional activity at 10 and 100 mA cm−2 with voltages of 1.52 and 1.88 V for overall water splitting and no obvious increase in current within 40 h. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Highly active 3DNP-Cu/ZnO SCRs were prepared by LPBF and dealloying for on-board MSR. • Interfacial area of Cu-ZnO and Cu+ molar ratio were modulated by induced activation. • High Cu+ molar ratio is favorable due to its enhancement of *CHOO generation. • 3DNP-Cu/ZnO SCRs achieved intensified mass and heat transfer. The development of efficient structural catalysts and reactors (SCRs) for on-board methanol steam reforming (MSR) has long been a focal point. Traditional MSR SCRs exhibit problems such as poor heat transfer, low catalyst loading, and coating delamination. In this study, novel three-dimensional graded nanoporous Cu/ZnO (3DNP-Cu/ZnO) SCRs were prepared via metal 3D printing technology and dealloying. For 3DNP-Cu/ZnO SCRs activated with MeOH/H 2 O steam, both the interfacial area of Cu-ZnO and the Cu+/(Cu0 + Cu+) molar ratio were greater than those of catalysts activated with H 2 /N 2 mixtures. The experimental results showed that a 3DNP-Cu/ZnO SCR activated with MeOH/H 2 O for 20 min exhibited a high methanol conversion rate of 98.3 % with a CO selectivity of 0.86 % (with a reaction temperature of 280 °C, a water-to-alcohol molar ratio of 1.3 and a weight hourly space velocity of 30 h−1). The superior catalytic activity was attributed to the high Cu+/(Cu++Cu0) ratio, which enabled the generation of *CHOO during the MSR reaction. Additionally, the 3DNP-Cu/ZnO SCRs demonstrated low pressure drops and high mechanical strengths. Computational fluid dynamics simulations showed that the gyroid lattice-structured catalyst achieved a high H 2 concentration due to its high mass and heat transfer. 3DNP-Cu/ZnO SCRs provide a new strategy for the preparation of MSR SCRs with broad application prospects. [ABSTRACT FROM AUTHOR]

A series of Rh-based catalysts with various crystalline phases (p25, anatase, and rutile) were prepared via the incipient-wetness impregnation method. It was found that these catalysts had different metal–support interactions. Hence, 1%Rh/p, 1%Rh/r, and 1%Rh/a exhibited methane, CO, and methanol selectivity, respectively. [ABSTRACT FROM AUTHOR]

[Display omitted] Catalytic hydrogenation of sulfur-containing substrates is an important and challenging reaction in the chemical industry. In this work, active carbon supported PdZn alloy catalyst was prepared by self-reduction method using zinc acetate as precursor without H 2 atmosphere. During the process of self-reduction, Zn2+ was firstly reduced to Zn0 at 300 °C by active carbon and reducing gas from the decompose of acetate under the promotion of metal Pd, and Zn0 further reacted with metal Pd to form PdZn alloy phase at 500 °C. These PdZn/AC-X catalysts showed the higher conversion and stability for the hydrogenation of 4-nitrothioanisole than the Pd/AC-600 catalyst. The excellent catalytic performance of PdZn/AC-600 catalyst can be attributed to formation of PdZn alloy, in which electron-rich Pd atoms weaken the binding ability between Pd and S and enhance the sulfur-resistance of catalyst. On the other hand, H 2 -TPR and DFT theory calculation further indicated that the PdZn alloy phase weakens the adsorption capacity of S. Compared with the Pd/AC-600 catalyst, the PdZn alloy phase in PdZn/AC-600 catalyst has not changed and only a small amount of sulfur-containing substrates deposited on the catalyst surface after three cycles. PdZn/AC-600 catalyst exhibited improved stability in the hydrogenation of 4-nitrothioanisole and can be used three cycles with little decrease in activity. [ABSTRACT FROM AUTHOR]

Inspired by natural wood, novel Ce 0 · 7 Zr 0 · 3 O 2 catalyst with hierarchical porous structure, W–CeZr, was fabricated using wood template method by utilizing catheter pores and pits in poplar. W–CeZr catalyst was then used for selective catalytic reduction of NO with NH 3 for the first time. Compared with conventional Ce 0 · 7 Zr 0 · 3 O 2 catalyst (C–CeZr), W–CeZr catalyst mimicked biological microstructure of wood and exhibited much greater low-temperature activity than C–CeZr, i.e., NO conversion for W–CeZr was 100% in the range of 250–350 °C, while that for C–CeZr was only 58.1% at 250 °C. Based on a series of characterization techniques, this effect can be attributed to an increase in surface area (m2·g−1), enrichment of Ce3+, and enrichment of surface-active oxygen species by 133.7%, 60%, and 59.5% compared to C–CeZr, respectively. In situ diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy results show that more activated reactants were present on the surface of W–CeZr because of its stronger surface acidity, as well as redox and oxygen storage abilities. [Display omitted] [ABSTRACT FROM AUTHOR]

Herein, we described a finding in the CO 2 hydrogenation reaction: by just altering the support interface types in Cu-based catalysts, selectivity could be totally reversed. CH 3 OH selectivity on Cu/ZnO-MgO catalyst was about 80%, whereas CH 4 selectivity on Cu/ZnO-CoO catalyst was around 98%. [Display omitted] • A new method for constructing multiple interface types was proposed. • CZM showed CH 3 OH selectivity, while CZC exhibited CH 4 selectivity. • Strength of basicity site at support interface can affect product selectivity. • The adsorption position of H 2 COO* on catalysts is key for CO 2 hydrogenation products. Growing interest has been shown in controlling the selectivity of CO 2 hydrogenation to produce specific compounds and fuels with additional value. However, it is challenging to selectively generate target products due to the complexity and diversity of the products in CO 2 hydrogenation reaction. Herein, we reported a finding in the CO 2 hydrogenation reaction: selectivity could be totally reversed by just altering support interface types on Cu-based catalysts. Cu/ZnO-MgO catalysts showed high CH 3 OH selectivity, while Cu/ZnO-CoO catalysts exhibited good selectivity of CH 4. According to in-depth characterization, varied basicity sites most likely as results of the different support interface types. Density functional theory (DFT) calculations pointed that support interface types altered the adsorption position of H 2 COO* on catalysts and affect the adsorption and activation of intermediates, and thus resulted in noticeably varied product selectivity. This study demonstrated the value of regulating CO 2 hydrogenation selectivity via support interface types on Cu-based catalysts, which can aid in the rational design of catalysts for not only CO 2 hydrogenation but also other significant reactions. [ABSTRACT FROM AUTHOR]

[Display omitted] • A silicon-free Cu catalyst with 94.8% EG at 210 °C and 95.6% ethanol at 280 °C. • Cu-N interaction maintained the key active sites Cu+ in hydrogen-rich atmosphere. • N doping provided anchoring and limiting for Cu species, thus enhanced stability. The hydrogenation of dimethyl oxalate (DMO) is a key step in the economical and eco-friendly synthesis of high value-added alcohols from syngas. In this study, a pyridinic-N-rich ultrathin carbon was employed as a support to construct a silicon-free Cu catalyst for highly efficient DMO hydrogenation. N-doped ultrathin carbon support with a two-dimensional structure provided sufficient anchoring sites for Cu species. More critically, abundant pyridinic-N (72.3%) maintained Cu in an electron-deficient state via electronic interactions between Cu and the carbon support, thereby preserving the vital active sites Cu+ during the hydrogen-rich reaction. The new silicon-free Cu catalyst (Cu/0.1 N-UC) demonstrated an ethanol selectivity that was 1.8 times higher than that of the commonly used Cu/SiO 2 catalyst. Additionally, the Cu/0.1 N-UC catalyst displayed superior stability and could convert the primary product to ethylene glycol by adjusting the reaction temperature. This study offers a novel approach for the development of promising silicon-free Cu catalysts for DMO hydrogenation. [ABSTRACT FROM AUTHOR]

• Impregnation method can replenish active components of spent VW/Ti catalyst. • Catalytic performance of VW/Ti catalyst can be even enhanced after impregnation. • Proper drying constructs more pores and achieves high distribution of V species. • Properly high V loading enhances SCR activity by forming polymeric V species. • The V4+/V5+ and O α /(O α +O β +O γ) values exhibit well linear correlation with E a. It is of great economic value and environmental significance to extend the service life of commercial SCR catalysts. Water and acid wash as well as thermal regeneration were often used to remove toxic substances (such as dust, metal sulfates and metal chlorides) residual on catalyst surface so as to reduce the replacement frequency of catalyst, but easily lead to the loss of active components. In this paper, impregnation method was used to supplement the lost active components of the spent honeycombed V 2 O 5 -WO 3 /TiO 2 (labeled as VW/Ti) catalyst, and the effects of drying duration and impregnation solution concentration on NH 3 -SCR performance of catalyst were studied. The results showed that the catalyst dried for 6 h at 110 °C exhibited the best deNO x activity and sulfur/water resistance. Further prolonging or shortening drying duration reduced the catalytic activity instead. It can be attributed that proper drying duration constructs abundant pore channels inside catalyst, optimizes active components dispersion, reduces diffusion resistance of reactants into the inner surface and provides more effective active sites on catalyst surface for adsorption and oxidation of reactants. With rise of V content in impregnation solution from 1.06 wt.% to 3.61 wt.%, deNO x activity as well as SO 2 /H 2 O resistance of catalyst improves at 150–300 °C. Besides, key influence factors are also discussed based on reaction kinetics analysis. [Display omitted] [ABSTRACT FROM AUTHOR]

• A combined method of DFT simulations and microkinetic modeling is employed. • The agglomeration of Co single atoms to Co dimer favors the conversion of CO2 and CH4. • The nucleation of Co single atoms weakens the coke-resistance ability of Co Ni(111) SAA catalyst. • CO* is the key species on Co Ni(111) SAAs surface. CO 2 reacting with CH 4 to produce value-added syngas CO and H 2 is an attractive approach to utilize CO 2 and achieve carbon neutralization. The present work employed the dispersion corrected density functional theory (DFT) and microkinetic modeling to investigate the influence of Co nucleation in Co Ni single atom alloy (SAA) on low-temperature methane dry reforming (DRM). It is found that the Co nucleation in Co Ni SAA did not alter the most favorable reaction path. That is, CH 4 is dehydrogenated to CH* step by step, then CH* is oxidized by O* from CO 2 direct decomposition to obtain CHO*, and finally CHO* is dehydrogenated to produce CO. For the decomposition of CO 2 , the direct decomposition of CO 2 prefers over the assisted decomposition of CO 2 by H* via COOH* or HCOO* intermediates decomposition to obtain the final product CO. Microkinetic modeling results reveal that the nucleation of single Co atoms to Co dimer or a surface Co layer favors the conversion of methane and CO 2 at 773 K but reduces the coke-resistance ability. Reverse water-gas shift does not change the key species on the surface but interferes the product distribution and surface rate-limiting step. [Display omitted] [ABSTRACT FROM AUTHOR]

• We create active Ni-SiO x interface sites. • The catalyst FE CO of > 90 % in a wide potential range. • Si-C and O-Si-C bonds favor formation of CO* intermediate and inhibition of HER. • This work shed more light on seeking practical catalysts for CO 2 RR. CO 2 electroreduction reaction (CO 2 RR) offers a promising route to scale up CO 2 -to-CO using renewable electricity and close the anthropogenic carbon cycle. To date, the undesirable hydrogen evolution reaction (HER) still occurs at the catalyst surface in CO 2 RR, diminishing CO 2 -to-CO production. In this work, we introduced silica on Ni to create active Ni-SiO x interface sites and prepared silica-modified nickel nanoparticles on carbon nanotubes (Si-Ni-CNTs-800) as a highly effective electrocatalyst for CO 2 -to-CO over a wide potential range. The catalyst achieved high CO Faradaic efficiency (FE CO) of > 90 % in a wide potential range from −0.6 to −1.1 V vs RHE with a maximum FE CO of 98 % at −0.9 V vs RHE with a CO partial current density of 21.5 mA cm−2 by using standard H-type cell, and the catalyst could be used stably at least 12 h. With the support of X-ray absorption fine structure (EXAFS) and spectroscopic analysis, we demonstrated that the chemical bonds of Si-C and O-Si-C in the catalysts favor CO 2 activation to form the CO* intermediate and inhibition of HER, finally enhanced CO 2 -to-CO conversion. [ABSTRACT FROM AUTHOR]

[Display omitted] • A spherical Cu/KCC-U catalyst that resembles an urchin was developed. • Distinctive structure enhanced the dispersion of Cu NPs and stability of Cu+. • Radial conical channels of catalyst reduced the likelihood of side reactions. • Synergistic effect of Cu/KCC-U endowed it with excellent hydrogenation capability. An urchin-like spherical Cu-based catalyst (Cu/KCC-U) with dendritic fibrous KCC-1 as support was developed using appropriate urea-assisted precipitation approach. Benefit from the radial conical channels, the dispersion of copper nanoparticles and the interaction between copper and support were greatly improved. As a result, the Cu/KCC-U catalyst owned plenty of highly dispersed Cu nanoparticles (4.10 nm), and the Cu+ ratio reached 77.38 %. The urchin-like spherical Cu/KCC-U catalyst, arising from the synergy of highly dispersed active copper species with 77.38 % Cu+ ratio and radial conical channel structure, demonstrated superior catalytic hydrogenation capacity, higher ethanol selectivity, and lower by-product selectivity when compared with reference Cu/KCC-I and Cu/SiO 2 -U catalysts. More crucially, the intimate interaction between copper species and KCC-1 support fibers enables the stable presence of Cu+ species in the hydrogenation reaction, resulting in the ultra-high stability of the catalyst. This urchin-like Cu/KCC-U provided a new perspective for designing and developing efficient hydrogenation catalysts with great selectivity and stability. [ABSTRACT FROM AUTHOR]

Direct synthesis of aromatics from syngas provides a promising approach for the production of fine chemicals from non-petroleum carbon resources. In this study, direct conversion of syngas into aromatics was investigated over a serial of bifunctional catalysts coupling ZnCrO x oxides and H-ZSM-5 zeolites with different morphologies. Detailed investigation showed that the CO conversion was positively correlated with the Brønsted acid sites, and the differences in aromatics selectivity and aromatics distribution on different bifunctional catalysts with different morphologies of H-ZSM-5 zeolites were attributed to the synergistic effects of acidity and particle size. For nano-type zeolites, changes in acidity might not have a significant effect on aromatics selectivity, while the transfer of intermediate species on coffin-type zeolites was mainly influenced by acidity. Moreover, for different morphology zeolites of nano-type n-Z5-125 and coffin-type c-Z5-100 with similar acidity, the side reactions in syngas aromatization on the former were 1.7 times higher than those on the latter. The reactants diffused more readily on TPAOH treated c-Z5-150-0.1 M, which promoted olefins cyclization and further increased the aromatics selectivity from 69.8% to 74.8%. [Display omitted] • The CO conversion in STA is positively correlated with the Brønsted acid sites. • H-ZSM-5 with external framework Al and short b-axis easily forms C 8 + aromatics. • TPAOH-treated c-Z5-150 zeolite is effective in enhancing the aromatics selectivity. [ABSTRACT FROM AUTHOR]