Rational Catalyst Design Research Articles

Engineering the coordination of Cu–Ni dual-atom catalysts to enhance the electrochemical CO2 overall splitting

Designing the coordination environment of heteroatoms around metal sites and optimizing the electronic structure of diatomic metal sites remain significant challenges in achieving efficient CO2 overall splitting. Herein, we report four configurations (Cu/Ni–N4C2, Cu/Ni–N2C4, Cu/Ni–N2C3 and Cu/Ni–N2C2) constructed by precise regulation of the coordination environment around bimetallic atoms. Cu/Ni–N2C2 showed high performance in electrochemical CO2 reduction (ECR) and water oxidation evolution reaction (OER). In the electrochemical CO2 overall splitting reaction, it achieved a Faraday efficiency of CO (FECO) of 98.0% at a low cell voltage of −2.9 V, significantly higher than widely reported values. Moreover, the FECO is above 90% over −2.7 to −4.1 V of cell voltages. Cu/Ni–N2C2 achieved long-term ECR stability of 110 h at −100 mA cm−2. Mechanism studies revealed that the change of coordination environment around the diatomic pairs moves the d-band center of the Ni atom closer to the Fermi level, thereby modulating the adsorption capacity of the catalysts to the reaction intermediates *COOH and *O. This work presents valuable insights into the rational design of diatomic catalysts and elucidates the intricate structure-performance relationship in advancing electrochemical CO2 overall splitting technology and energy-conversion applications.

Atmosphere-driven oriental regulation of Ru valence for boosting alkaline water electrolysis

Modulating the electronic characteristics of nanomaterials has been key to advancing sustainable energy technologies. In this study, we controlled the Ru electronic properties of NiRuOx by varying the calcination atmospheres (Air and Argon), resulting in two distinct electrocatalysts: NiRuOx-O2 with Ru4+ species and NiRuOx-Ar with Ru0 species as the main component. We established the relationship between the valence of Ru and its HER and OER catalytic activity as NiRuOx for example. Specifically, NiRuOx-Ar with metallic Ru demonstrates better alkaline HER activity with a smaller overpotential (94 mV) at 100 mA cm−2 than NiRuOx-O2 with Ru4+ due to the reduced Ru0 superiority towards H*. Conversely, NiRuOx-O2 shows superior alkaline OER performance with only 275 mV overpotential at 100 mA cm−2 compared with that of NiRuOx-Ar (383 mV) due to Ru4+ receiving electrons from Ni species and reduced Ru–O covalence. The NiRuOx-O2//NiRuOx-Ar electrolyzer in 1 M KOH achieves 10 mA cm−2 at 1.475 V with 100 h durability, surpassing the RuO2//Pt/C cell (1.516 V). Revealing the correlation between Ru valence and activity offers important insights for the rational design of Ru-based catalysts for HER and OER.

Iron-Induced vacancy and electronic regulation of nickle phosphides for ampere-level alkaline water/seawater splitting

Rational design of non-precious metal catalysts can accelerate the oxygen evolution reaction (OER) kinetics. Herein, inspired by theoretical analysis, in-situ Fe-doped Ni2P/Ni12P5 with rich P vacancies (Fe-NiPx) is designed and constructed, in which the production of P vacancies is induced by Fe doping. Relevant characterizations confirm that the Fe doping and P vacancies can co-adjust the crystal and electronic structures, thereby optimizing the reconstruction behavior and improving the intrinsic activity of reconstructed-derived Ni(Fe)OOH. As a result, it exhibits excellent OER activity with overpotentials of 256 and 276 mV to achieve the current density of 100 mA cm−2 in 1 M KOH solutions and alkaline seawater, respectively. Furthermore, the Fe-NiPx electrode only requires 1.861 and 1.889 V to drive the 1.0 A cm−2 overall water and seawater splitting, respectively, and maintains stable output as high as 1000 h. Also, to demonstrate the great application potential, green energy-to-hydrogen systems are established. Electrochemical tests and theoretical calculations reveal that reconstructed-Fe-NiPx facilitates the OER kinetics under the adsorbate evolution mechanism (AEM) pathway, with optimized adsorption free energies of intermediates and reduced reaction energy barriers. This work provides new insights into efficient water and seawater splitting through in-situ heteroatom doping and vacancy engineering.

Hydrogenation Reaction Mechanisms on Ni-Doped MoS2 Catalysts: A Density Functional Theory Study of Sulfur Edge Engineering and Coregulated Electronic Effects.

Precise modulation of local interatomic interactions affecting the electronic structure is an important method to control the catalytic activity and reaction pathways. In this study, we focused on the hydrogenation reaction of naphthalene and employed density functional theory calculations to investigate the specific influence of electronic effects triggered by the coregulation of Ni and sulfur edge engineering on the hydrogenation performance of Ni-doped MoS2 at different edge sulfur coverages (Ni-MoS2-X-θs). Our findings reveal that the interaction between Ni and S in the catalyst matrix material modifies the local electronic structure surrounding the sulfur atoms in the active site. Notably, Ni doping facilitates significant electron transfer, altering the charge and the electronic states at the catalyst edge. This, in turn, affects the adsorption capacity and reactivity of the catalyst, thereby reducing the energy barrier of the hydrogenation reaction. Furthermore, we paid particular attention to the modulation of catalytic activity and reaction pathways under the Eley-Rideal (E-R) mechanism. Interestingly, the sulfur coverage exhibited a nonlinear relationship with the adsorption and activation properties of the probe molecule. Typically, changes in the Mo edge sulfur coverage probability of Ni-MoS2-X-θs have a greater impact on the activation properties. Through comprehensive studies, we demonstrated that both compositional and structural factors must be considered when tailoring the catalytic performance. Importantly, adjusting the ratio of marginal sulfur atoms to metal atoms to 1:1 can effectively enhance the catalytic activity. This study provides valuable insights into the electronic effects regulating the hydrogenation reaction activity of MoS2-based catalysts. It also opens the way for the rational design of novel hydrogenation catalysts, offering a new strategy for optimizing the catalytic performance.

Manipulating C-C coupling pathway in electrochemical CO2 reduction for selective ethylene and ethanol production over single-atom alloy catalyst.

Manipulation C-C coupling pathway is of great importance for selective CO2 electroreduction but remain challenging. Herein, two model Cu-based catalysts, by modifying Cu nanowires with Ag nanoparticles (AgCu NW) and Ag single atoms (Ag1Cu NW), respectively, are rationally designed for exploring the C-C coupling mechanisms in electrochemical CO2 reduction reaction (CO2RR). Compared to AgCu NW, the Ag1Cu NW exhibits a more than 10-fold increase of C2 selectivity in CO2 reduction to ethanol, with ethanol-to-ethylene ratio increased from 0.41 over AgCu NW to 4.26 over Ag1Cu NW. Via a variety of operando/in-situ techniques and theoretical calculation, the enhanced ethanol selectivity over Ag1Cu NW is attributed to the promoted H2O dissociation over the atomically dispersed Ag sites, which effectively accelerated *CO hydrogenation to form *CHO intermediate and facilitated asymmetric *CO-*CHO coupling over paired Cu atoms adjacent to single Ag atoms. Results of this work provide deep insight into the C-C coupling pathways towards target C2+ product and shed light on the rational design of efficient CO2RR catalysts with paired active sites.

Cation‐Vacancy Engineering Modulated Perovskite Oxide for Boosting Electrocatalytic Conversion of Polysulfides

AbstractLithium‐sulfur batteries face challenges like polysulfide shuttle and slow conversion kinetics, hindering their practical applications in renewable energy storage and electric vehicles. Herein, a solution to solve this issue is reported by using a cation vacancy engineering strategy with rational synthesis of La‐deficient LaCoO3 (LCO‐VLa). The introduction of cation vacancies in LCO‐VLa modifies the geometric structure of coordinating atoms, exposing Co‐rich surface with more catalytically active surfaces. Meanwhile, the d‐band center of LCO‐VLa shifts toward the Fermi level, enhancing polysulfide adsorption. Furthermore, multivalent cobalt ions (Co3+/Co4+) induced by charge compensation enhance the electrical conductivity of LCO‐VLa, accelerating electron transfer processes and improving catalytic performance. Theoretical calculations and experimental characterizations demonstrate that La‐deficient LCO‐VLa effectively suppresses the polysulfide shuttle, reduces the energy barrier for polysulfide conversion, and accelerates redox reaction kinetics. LCO‐VLa‐based batteries demonstrate exceptional rate performance and cycling stability, retaining 70% capacity after nearly 500 cycles at 1.0 C, with a minimal decay rate of 0.055% per cycle. These findings highlight the significance of cation vacancy engineering for exploring precise structure‐activity relationships during polysulfides conversion, facilitating the rational design of catalysts at the atomic level for lithium‐sulfur batteries.

Transient Kinetic Investigation of Chain Growth and the Accumulation of Surface Carbon during CO Hydrogenation on Cobalt Catalysts

CO hydrogenation is a promising approach for the storage of renewable energy in the form of hydrocarbons via the Fischer‐Tropsch synthesis (FTS). Since transient operation of FTS reactors might be necessary and even be beneficial, transient kinetics for a rational catalyst and reactor design are essential. In order to advance the development of such transient kinetics, the periodic transient kinetics (PTK) method was applied to the CO hydrogenation on a Co/TiO2 catalyst under FT‐like conditions. It was revealed that there are two carbon species of different reactivity, Cα and Cβ, present on the catalyst surface during the reaction. Cα forms fast within a few seconds and is highly reactive, while Cβ forms slowly, is accumulating on the surface over a longer time and imposes an inhibiting effect. The results indicate an important role of the Cβ species to chain growth and the formation of C2+ products. Finally, the transient experimental results are evaluated based on a material balance and the amounts of Cα and Cβ present on the catalyst surface during the reaction were determined.

Surface restructuring and predictive design of heterogeneous catalysts.

Heterogeneous catalysts, which often consist of metal nanoparticles loaded on supports such as metal oxides, can undergo several types of restructuring under reaction and catalytic conditions. Advanced characterizations now allow the surface structure of a catalyst in a gas phase to be determined to some extent. Metal nanoparticles may experience changes in shape, surface structure and composition, and atomic packing in response to the pressure of a reactant or product gas, temperature, and reaction between the catalyst surface and gas. Metal oxide supports can partially or fully encapsulate metal nanoparticles, altering their electronic structure and reactivity. Restructuring is a main approach to creating active catalytic sites. The rational design of catalysts must anticipate that such restructurings can occur under reaction or catalytic conditions and gain knowledge of how they occur. It is expected that computational studies can predict such restructurings and that advanced synthesis may be used to prepare pristine catalysts with enhanced resistance to restructurings.

Two major deactivation mechanisms in carbon-based advanced oxidation processes (AOPs) dominated by electron-transfer pathway (ETP)

Carbon-based advanced oxidation processes through electron-transfer pathway are regarded as a green technology for efficient and selective oxidation of the emerging pollutants in complex water matrixes. Despite achievements in the superior activity and selectivity for organic degradation of carbocatalysts, their stabilities remain unsatisfactory, primarily because of the underexplored deactivation mechanisms. This study identifies two distinct deactivation mechanisms. The first is Oxidant Deactivation, due to overoxidation by the oxidant and predominantly affected by the concentration of oxidant. The other is Organic Deactivation, primarily caused by attachment of organic byproducts on catalyst surface, which reduces the overall oxidation potential of carbon/persulfate complex, instead of covering the surface “active sites”. Furthermore, the deactivation mechanisms mainly depend on intrinsic catalytic pathways: Oxidant Deactivation originates from the adjacent transfer pathway and Organic Deactivation from the electron shuttle pathway. Finally, the relationship between the deactivation mechanisms and carbon configuration (sp2/sp3) is revealed, and a catalyst with optimal activity and stability can be achieved through properly regulating the sp2/sp3 ratio. Results indicate that different protective strategies and application scenarios should be adopted for different systems to extend their lifespan in real wastewater treatment. This work sheds light on rational catalyst design toward advanced water purification systems with high efficiency and stability.

N-doped Z-scheme heterojunctions on cobalt foam for enhanced photocatalytic degradation of levofloxacin and reduction of hexavalent chromium: Insights into charge separation and catalytic mechanisms

The transfer of photoelectrons across heterogeneous materials stands as a cornerstone process within the domain of photocatalysis. Elucidating the mechanisms underlying electron transfer at heterojunction interfaces provides profound insights that are crucial for the rational design of efficient catalysts. In this study, we employ a hierarchical synthesis approach to fabricate N-doped Z-scheme heterojunctions directly on the surface of cobalt foam (CoF). Both experimental observations and density functional theory (DFT) calculations reveal that N-doped CoS2 nanosheets exhibit asymmetric charge distribution, functioning as localized electron traps. Further analysis of differential charge density elucidates that positive charges are predominantly concentrated in proximity to N-CoS2, whereas negative charges accumulate near ZnO, indicating substantial charge exchange between these two phases. The integration of a potent built-in electric field upon illumination facilitates the splitting of photogenerated carriers in both transverse and longitudinal directions, thereby enabling their effective separation and migration. The CoF@N-CS@ZO composites demonstrated a remarkable capacity for simultaneous degradation and reduction, achieving a 93.6 % degradation of levofloxacin (LEV) and a 96.9 % reduction of hexavalent chromium (Cr(VI)) under visible light irradiation for 85 min. Furthermore, due to the active species being anchored on the surface of the CoF, which serves as a recyclable substrate, the composites could be directly recycled post-use. Notably, CoF@N-CS@ZO maintained an efficiency of over 80 % for both LEV degradation and Cr(VI) reduction even after undergoing more than ten cycles. This research elucidates the intricate interplay of the synergistic N-doped built-in electric field on the charge transfer process, offering profound insights into the targeted design of charge-modulated materials for enhanced photocatalytic performance.

An efficient Ni-Mg/HNTs catalyst for CO2 methanation prepared by sol-gel method assisted with citric acid

Developing a stable and effective Ni-based catalyst for low-temperature CO2 methanation remains a significant challenge. This study presents the synthesis of a range of MgO-promoted Ni-based catalysts supported on natural halloysite nanotubes (HNTs) through a sol-gel method assisted by citric acid. At 275°C, Ni-Mg/HNTs-1.0 CA exhibits the highest CO2 conversion (88.5%) and CH4 selectivity (98.4%). The sufficient basic sites and Ni0 sites of Ni-Mg/HNTs-1.0CA are beneficial for CO2 activation and H2 dissociation, leading to high activity at low temperatures. Additionally, Ni-Mg/HNTs-1.0 CA exhibits better anti-sintering ability during 100 h reaction, attributed to the increased interaction between metal and support. The in-situ DRIFTS results show that Ni-Mg/HNTs-1.0 CA mainly follows both formate and CO pathways, and the rapid transformation of intermediates causes superior catalytic performance. This work offers a rational design of stable and active catalysts for low-temperature CO2 methanation.

State of the Art and Challenges in Complete Benzene Oxidation: A Review.

Increased levels and detrimental effects of volatile organic compounds (VOCs) on air quality and human health have become an important issue in the environmental field. Benzene is classified as one of the most hazardous air pollutants among non-halogenated aromatic hydrocarbons with toxic, carcinogenic, and mutagenic effects. Various technologies have been applied to decrease harmful emissions from various sources such as petrochemistry, steel manufacturing, organic chemical, paint, adhesive, and pharmaceutical production, vehicle exhausts, etc. Catalytic oxidation to CO2 and water is an attractive approach to VOC removal due to high efficiency, low energy consumption, and the absence of secondary pollution. However, catalytic oxidation of the benzene molecule is a great challenge because of the extraordinary stability of its six-membered ring structure. Developing highly efficient catalysts is of primary importance for effective elimination of benzene at low temperatures. This review aims to summarize and discuss some recent advances in catalyst composition and preparation strategies. Advantages and disadvantages of using noble metal-based catalysts and transition metal oxide-based catalysts are addressed. Effects of some crucial factors such as catalyst support nature, metal particle size, electronic state of active metal, redox properties, reactivity of lattice oxygen and surface adsorbed oxygen on benzene removal are explored. Thorough elucidation of reaction mechanisms in benzene oxidation is a prerequisite to develop efficient catalysts. Benzene oxidation mechanisms are analyzed based on in situ catalyst characterization, reaction kinetics, and theoretical simulation calculations. Considering the role of oxygen vacancies in improving catalytic performance, attention is given to oxygen defect engineering. Catalyst deactivation due to coexistence of water vapor and other pollutants, e.g., sulfur compounds, is discussed. Future research directions for rational design of catalysts for complete benzene oxidation are provided.

Dual Near-Infrared-Response S-Scheme Heterojunction with Asymmetric Adsorption Sites for Enhanced Nitrogen Photoreduction.

Photocatalytic nitrogen reduction reaction (PNRR) holds immense promise for sustainable ammonia (NH3) synthesis. However, few photocatalysts can utilize NIR light that carries over 50% of the solar energy for NH3 production with high performance. Herein, a dual NIR-responsive S-scheme ZnCoSx/Fe3S4 heterojunction photocatalyst is designed with asymmetric adsorption sites and excellent PNRR performance. The heterojunction possesses a hollow-on-hollow superstructure: Fe3S4 nanocrystal-modified ZnCoSx nanocages as building blocks assemble into spindle-shaped particles with a spindle-like cavity. Both Fe3S4 and ZnCoSx are NIR active, allowing efficient utilization of full-spectrum light. Moreover, an S-scheme heterojunction is constructed that promotes charge separation. In addition, the Fe/Co dual-metal sites at the interface enable an asymmetric side-on adsorption mode of N2, favoring the polarization and activation of N2 molecules. In combination with the promoted mass transfer and active site exposure of hollow superstructure, a superior PNRR performance is achieved, with a high NH3 evolution rate of 2523.4 µmolg-1h-1, an apparent quantum yield of 9.4% at 400nm and 8% at 1000nm, and a solar-to-chemical conversion efficiency of 0.32%. The work paves the way for the rational design of advanced heterojunction catalysts for PNRR.

Localized Electron Redistribution in Methanol Molecules over the Sea Urchin-like Tricobalt Tetroxide/Copper Oxide Nanostructures for Fast Hydrogen Release.

Catalytic methanolysis of ammonia borane (NH3BH3) is a prospective technology in the field of hydrogen energy in which hydrogen production and hydrogen storage can be integrated together. The splitting of the O-H bond is identified as the rate-determining step (RDS) in this reaction. Thus, a deep understanding of the relationship between the electronic structure of the catalyst, especially the localized electron density of active sites, and the breaking behaviors of the O-H bond is of extreme importance for the rational design of robust catalysts for the reaction. In this work, sea urchin-like tricobalt tetroxide/copper oxide (Co3O4/CuO) nanostructures with rich oxygen vacancies (Ov) were fabricated by a simple synthetic route. In NH3BH3 methanolysis, the optimal Co3O4/CuO sample exhibited ultrahigh catalytic activity with a turnover frequency (TOF) of 87.5 min-1. Interestingly, when NH3BH3 methanolysis was carried out under visible-light illumination, the TOF further increased to 116.4 min-1, which is the highest TOF value among those of the noble-metal-free catalysts ever documented in the literature. Theoretical calculation results evidenced that the Cu site in the Co3O4/CuO sample was in charge of the adsorption and activation of methanol molecules. Both the Ov and visible-light illumination can help electrons on the Cu site flow to the adsorbed methanol molecule, thus leading to localized electron redistribution of the methanol molecule and the extension of the O-H bond. The cooperation of Ov and visible light makes splitting of the O-H bond easier, which is favorable for fast hydrogen release from NH3BH3 methanolysis. This study helps us to gain an insight into the influence of localized electron redistribution of methanol molecules on the RDS, which conduces to the rational design of highly effective nanocatalysts. Moreover, the coinduction strategy for localized electron redistribution with oxygen vacancy engineering and visible-light illumination opens up a route to boost catalytic activity in NH3BH3 methanolysis.

NMR Relaxation to Probe Zeolites: Mobility of Adsorbed Molecules, Surface Acidity, Pore Size Distribution and Connectivity.

Unique structural and chemical properties, such as ion exchange, developed inner surface, etc., as well as the wide possibilities and flexibility of regulating these properties, cause a keen interest in zeolites. They are widely used in industry as molecular sieves, ion exchangers and catalysts. Current trends in the development of zeolite-based catalysts include the adaptation of their cationic composition, acidity and porosity for a specific catalytic process. Recent studies have shown that mesoporosity is beneficial to the rational design of catalysts with controlled product selectivity and an improved catalyst lifetime due to its efficient mass-transport properties. Nuclear magnetic resonance (NMR) has proven to be a reliable method for studying zeolites. Solid-state NMR spectroscopy allows for the quantification of both Lewis and Brønsted acidity in zeolite catalysts and, nowadays, 27Al and 29Si magic angle spinning NMR spectroscopy has become firmly established in the set of approved methods for characterizing zeolites. The use of probe molecules opens up the possibility for the indirect measurement of the characteristics of acid sites. NMR relaxation is less common, although it is especially informative and enlightening for studying the mobility of guest molecules in the porous matrix. Moreover, the NMR relaxation of guest molecules and NMR cryoporometry can quantify pore size distribution on a broader scale (compared to traditional methods), which is especially important for systems with complex pore organization. Over the last few years, there has been a growing interest in the use of 2D NMR relaxation techniques to probe porous catalysts, such as 2D T1-T2 correlation to study the acidity of the surface of catalysts and 2D T2-T2 exchange to study pore connectivity. This contribution provides a comprehensive review of various NMR relaxation techniques for studying porous media and recent results of their applications in probing micro- and mesoporous zeolites, mainly focused on the mobility of adsorbed molecules, the acidity of the zeolite surface and the pore size distribution and connectivity of zeolites with hierarchical porosity.

Nature-Inspired N, O Co-Coordinated Manganese Single-Atom Catalyst for Efficient Hydrogen Peroxide Electrosynthesis.

The two-electron oxygen reduction reaction (2e- ORR) is a pivotal pathway for the distributed production of hydrogen peroxide (H2O2). In nature, enzymes containing manganese (Mn) centers can convert reactive oxygen species into H2O2. However, Mn-based heterogeneous catalysts for 2e- ORR are scarcely reported. Herein, we developed a nature-inspired single-atom electrocatalyst comprising N, O co-coordinated Mn sites, utilizing carbon dots as the modulation platform (Mn CD/C). As-synthesized Mn CD/C exhibited exceptional 2e- ORR activity with an onset potential of 0.786 V and a maximum H2O2 selectivity of 95.8 %. Impressively, Mn CD/C continuously produced 0.1 M H2O2 solution at 200 mA/cm2 for 50 h in the flow cell, with negligible loss in activity and H2O2 faradaic efficiency, demonstrating practical application potential. The enhanced activity was attributed to the incorporation of Mn atomic sites into the carbon dots. Theoretical calculations revealed that the N, O co-coordinated structure, combined with abundant oxygen-containing functional groups on the carbon dots, optimized the binding strength of intermediate *OOH at the Mn sites to the apex of the catalytic activity volcano. This work illustrates that carbon dots can serve as a versatile platform for modulating the microenvironment of single-atom catalysts and for the rational design of nature-inspired catalysts.

Efficient Hydrodeoxygenation of Lignin-Derived Phenolic Compounds Over Ru-Based Catalyst with Biochar and Al2O3 as Composite Support.

Hydrodeoxygenation (HDO) is a common strategy for upgrading lignin-derived phenolic compounds into high-quality liquid fuels, and the support rational design of HDO catalysts is critical to achieve a good reaction performance. This work proposed a novel Ru-based catalyst with biochar and Al2O3 as composite support. The addition of biochar can enlarge the porous structure, and the addition of Al2O3 can enhance the acid property of the support. By regulating the content of biochar and Al2O3 components, Ru/CA-2 catalyst achieved the best HDO performance of lignin-derived phenolic compounds, with the optimal component balance of 50 %C and 50 %Al2O3. This catalyst possesses the high Ru metal dispersion (1.38 nm particle size) to activate the hydrogen source, the moderate acid property to suppress carbon deposition and the abundant oxygen vacancy to promote substrate adsorption at the same time. 99.9 % conversion of guaiacol is obtained at 230 °C, with 99.9 % selectivity towards cyclohexane. Ru/CA-2 catalyst also has a good recyclability, with no obvious activity loss after five runs. Furthermore, in the application of catalytic lignin-oil HDO, the content of hydrocarbons increase from 10.7 % to 95.7 %, showing great potential on the industrial usage.

Boosting the catalytic performance of MnOx in acetone oxidation by weakening the Mn[sbnd]O bond strength

Manganese oxides (MnOx) exhibit considerable potential in the catalytic degradation of volatile organic compounds (VOCs) due to their excellent catalytic activity, superior stability and economic cost. In this work, a two-step calcination strategy was developed to prepare MnOx/CeO2 catalysts with low MnO bond strengths and highly active lattice oxygens. The obtained Mn4Ce1-NA after the optimization has a smaller grain size, enhanced specific surface area and weakened MnO bonds, which is attributed to the in situ restriction of the manganese oxides by the two-step calcination. Moreover, the entrance of Ce into the MnOx lattice further weakened the MnO bonds, leading to superior low-temperature reducibility and lattice oxygen activity, which effectively promoted the catalytic activity of the catalysts. The optimal samples displayed outstanding acetone degradation performance, capable of completing 90 % acetone conversion at 172 °C. The catalyst also exhibits excellent stability, with the conversion of acetone maintained at around 95 % for 64 h. This work contributes to a deeper understanding of reactive oxygen species in the catalytic oxidation of VOCs, while providing a new strategy for the rational design of efficient catalysts for the oxidation of VOCs.

High‐Throughput Screening of Dual‐Atom Catalysts for Methane Combustion: A Combined Density Functional Theory and Machine‐Learning Study

AbstractCeria‐supported precious metal catalysts have undergone extensive investigation for the catalytic methane combustion. However, it remains a significant challenge to achieve both highly synergistic oxidation activity and efficient atom utilization remains a challenge for commonly used supported nanoparticles and single‐atom catalysts. Dual‐atom catalysts (DACs) emerges as a frontier of advanced catalysts, presenting unique catalytic properties that benefit from the synergy of neighboring metal sites. In this study, 361 ceria‐supported DACs (M1M2/CeO2) encompassing combinations of 19 transition metals are systematically explored. Using high‐throughput density functional theory calculations, the structures, stability as well as activity of M1M2/CeO2 are assessed. Notably, Au1Ga1/CeO2 is identified as a promising DAC exhibiting high activity for methane total oxidation, substantiated by comprehensive DFT‐calculated reaction pathways. Furthermore, employing six machine‐learning algorithms, the structure‐properties relationship is explored within ceria‐based DACs and highlight the importance of oxidation states and atomic radii of doped metals as the descriptors. The trained model by computational dataset exhibits high accuracy and predict a more active Mn1Au1/CeO2 than those screened using only DFT datasets. The high‐throughput strategy demonstrated in this work not only provides insights into the rational design of methane oxidation catalysts, but also paves the way for exploring DACs for diverse applications.

Regulating the Microenvironment of Zn‐Based Metal‐Organic Framework for Enhanced CO2 Electroreduction to Formate

Electrocatalytic CO2 reduction (ECR) has emerged as one of the most promising strategies to alleviate the energy crisis and CO2 pollution, for which a wide variety of catalysts are under development. Metal‐organic frameworks (MOFs) with clear and designable structures are an excellent platform for ECR. Here, two isostructural N, O‐coordinated Zn‐MOFs, FJU‐126‐4F and FJU‐126‐CH3, based on terephthalic acid ligand with different groups (one is ‐4F, the other is ‐CH3) on the benzene ring, have been constructed for ECR catalysts. Significantly, the different functional groups make the performance difference of ECR. The maximum Faraday efficiency of formate (FEformate) for FJU‐126‐4F is 60.5% with the partial current density of formate (jformate) of ‐19.35 mA cm‐2 at ‐1.47 V, while the optimum FEformate of FJU‐126‐CH3 is 50.2% with the jformate of ‐10.04 mA cm‐2 at ‐1.57 V. The work provides insight into the rational design of MOF catalysts for ECR.