Effects of S‐Vacancy on the CO 2 RR in Co‐Doped SnS 2 Monolayer

One-dimensional covalent organic framework as a robust carrier for enhanced lipase immobilization and catalytic performance

10.31635/ccschem.021.202101063

Hydrazine-driven cation valence regulation and defect engineering in CeVO4 for highly efficient reduction of organic dyes and heavy metal pollutants in the dark

Carbon neutrality is a fundamental strategy for achieving the sustainable development of human society. Catalyzing CO2 reduction into various high-value-added fuels serves as an effective pathway to achieve this strategic objective. Atom-dispersed catalysts have received extensive attention due to their maximum atomic utilization, high catalytic selectivity, and exceptional catalytic performance. Dual-atom catalysts (DACs), as an extension of single-atom catalysts (SACs), not only retain the advantages of SACs, but also produce many new properties. This review initiates its exploration by elucidating the mechanism of CO2 reduction reaction (CO2RR) from CO2 adsorption and CO2 activation. Then, a comprehensive summary of recently developed preparation methods of DACs is presented. Importantly, the mechanisms underlying the promoted catalytic performance of DACs in comparison to SACs are subjected to a comprehensive analysis from adjustable adsorption capacity, tunable electronic structure, strong synergistic effect, and enhanced spacing effect, elucidating their respective superiorities in CO2RR. Subsequently, the application of DACs in CO2RR is discussed in detail. Conclusively, the prospective trajectories and inherent challenges of CO2RR are expounded upon concerning the continued advancement of DACs. This thorough review not only enhances the comprehension of DACs within CO2RR but also accentuates the prospective developments in the design of sophisticated catalytic materials.

Mechanism of electrocatalytic CO2 reduction reaction by borophene supported bimetallic catalysts

Herein, a coherent study of the intrinsic kinship between electronic and geometric structures was performed using Pt/CeO 2 catalysts. CeO 2 ‐supported Pt nanoclusters (1.7 nm) were synthesized with two distinct exposed crystal facets, CeO 2 (110) and CeO 2 (100), and catalytic activity was tested by a water–gas shift reaction. The CO conversion was achieved higher using the Pt/CeO 2 (110) catalyst (83%) with a rate of the reaction and turnover frequency of 26.87 mol CO /g Pt /h and 3.20 s −1 at 275 °C, respectively. The long‐term stability using the Pt/CeO 2 (110) catalyst was performed for 120 h, and the results show that the Pt/CeO 2 (110) catalyst is still stable without significant CO conversion drop. The physicochemical characterization reveals a moderately embedded structure at the interface of the metal and support, and Pt atoms move into within three to four atomic layers of the crystal lattice of CeO 2 (110). Consequently, the electron density in the Pt species decreases, and the formation of Pt δ+ ‐O v ‐Ce 3+ interfacial sites increases. The theoretical studies integrated with experimental study evidence that the stronger charge movement interfacial species (Pt δ+ ‐O v ‐Ce 3+ ) and higher oxygen vacancy concentration in Pt/CeO 2 (110) catalyst regulated by the inter‐embedded interface structure maximize the adsorption of CO and trigger the H 2 O dissociation, responsible for the exceptional catalytic performance.

Hollow ZSM-5 zeolite grass ball catalyst in methane dehydroaromatization: One-step synthesis and the exceptional catalytic performance

Chemical conversion of CO2 into cyclic carbonates using a versatile and efficient all-in-one catalyst integrated with DABCO ionic liquid and MIL-101(Cr)

Atomic single metal sites riveted on carbon materials have drawn ever-growing interest in various electrocatalytic and inorganic transformation processes owing to their exceptional catalytic performance and selectivity. However, there are challenges for the generic and controlled fabrication of such catalysts. Herein, a general, flexible and versatile cascade-locking route is developed to construct metal single atom sites on hierarchical nitrogen-doped superstructured carbons (M SAs-N/SC) via pyrolysis of a unique metallo-supramolecular organic framework precursor, in which primary metal complexes of 2, 2'-bicinchoninic acid (BCA) and target metal ions using metal-N coordination bonds are ulteriorly crosslinked with melamine (MA) units through intramolecular N─H∙∙∙O and O─H∙∙∙N hydrogen bond interactions. Importantly, a series of atomic-level metal site catalysts can be successfully fabricated, demonstrating the remarkable adjustability and generality of this method. When acting as a heterogeneous catalyst in C-H oxidation and alkene epoxidation reactions, such Fe SAs-N/SC exhibited high selectivity, reusability, and substrate tolerance. Moreover, the as-prepared Fe SAs-N/SC catalyst delivered exceptional catalytic performance for the electrocatalytic CO2 reduction reaction. The finding puts forward a brand-new and universal way to synthesize single atom metal site catalysts for a wide range of potential applications.

Cu surfaces are known for their ability to electrochemically convert CO2 and CO into multicarbon (C2+) products. Although the impact of the electrolyte alkalinity on the electrochemical CO2 and CO reduction reactions (CO2RR and CORR, respectively) has been extensively investigated on Cu surfaces, systematic investigation of the pH dependence of the surface Cu speciation has been lacking. Herein, we demonstrate for the first time the pH dependence of Cu surface speciation and CO adsorption configuration in weakly to strongly alkaline electrolytes using in situ surface enhanced Raman spectroscopy. Oxygen-containing species, e.g., CuOx/(OH)y, are absent in near-neutral electrolyte of KHCO3 (pH = 8.9), and their onset potential becomes more positive with increasing the alkalinity of electrolytes. Concurrently, adsorbed CO transitions from atop-bonded (COatop) to bridge-bonded configuration (CObridge) as the pH of the electrolyte increases. CO is proposed to adsorb in the atop configuration only on Cu sites without neighboring oxygen-containing species, while the appearance of the CObridge band correlates with the presence of the oxygen-containing species. Surface speciation on Cu microparticles (Cu MPs) and oxide-derived Cu (OD-Cu) are similar in all the electrolytes investigated, while the CO adsorption bands show subtle differences on these two surfaces, reflecting variations in the microenvironment of CO adsorbed in the same configuration. Selectivity for C2+ products in the CORR on Cu MPs increases with the electrolyte alkalinity at −0.4 VRHE, which correlates with the presence of the oxygen-containing Cu species. However, the presence of the oxygen-containing Cu species alone is shown to be an unreliable predictor of the CORR performance on Cu MPs and OD-Cu, which could be attributed to the difference in the microenvironment of the surface Cu sites. Results reported in this work highlight that the assumption that the surface Cu speciation under reducing potentials is independent of the electrolyte pH must be treated with caution.

Amorphous nanomaterials, once considered structurally disordered, are now recognized for exceptional catalytic performance, yet their atomic‐scale origins remain elusive. Here, we combine atom probe tomography (APT), theoretical simulation, and operando spectroscopy to reveal the hidden architecture of amorphous Ni(OH) 2 nanosheets (a‐Ni(OH) 2 NSs)—a highly active and durable catalyst for alkaline seawater electrolysis. As cathodes in anion exchange membrane water electrolyzers, a‐Ni(OH) 2 NSs deliver a remarkably low cell voltage of 1.89 V at 1.0 A cm − 2 , outperforming crystalline Ni(OH) 2 (2.53 V) and commercial Pt/C (2.39 V), while sustaining over 1000 h of stable operation with negligible decay (<0.02 mV h −1 ). APT enables 3D, atom‐by‐atom mapping—including hydrogen—revealing four distinct short‐range order (SRO) motifs with thickness‐dependent distributions. These motifs act synergistically: surface O–Ni–OH SROs promote water dissociation, interior Ni–OH SROs optimize proton reduction, and bridging O–Ni–O and Ni–OH 2 SROs accelerate proton transport via hydrogen‐bond networks. This coordinated motif network fully accounts for the exceptional performance, transforming the view of amorphous materials from “black boxes” to atomically designable systems. Our findings establish APT as a transformative platform for uncovering functional motifs in amorphous catalysts, paving the way for rational design of next‐generation materials for sustainable energy conversion.

MXenes, a novel class of two-dimensional materials, have garnered significant attention for their promising electrocatalytic properties in various energy conversion applications such as water splitting, fuel cells, metal-air batteries, and nitrogen reduction reactions. Their excellent electrical conductivity, high specific surface area, and versatile surface chemistry enable exceptional catalytic performance. This review highlights recent advancements in the design and application strategies of MXenes as electrocatalysts, focusing on key reactions including hydrogen evolution reaction (HER), oxygen evolution reaction (OER), oxygen reduction reaction (ORR), and nitrogen reduction reaction (NRR). We discuss the tunability of MXenes' layered structures and surface properties through surface modification, MXene lattice substitution, defect and morphology engineering, and heterostructure construction. Despite the considerable progress, MXenes face challenges such as restacking during catalysis, stability issues, and difficulties in large-scale production. Addressing these challenges through innovative engineering approaches and advancing industrial synthesis techniques is crucial for the broader application of MXene-based materials. Our review underscores the potential of MXenes in transforming electrocatalytic processes and highlights future research directions to optimize their catalytic efficiency and stability.

Structurally ordered high‐entropy intermetallics (HEIs) have garnered increased attention due to their unique physicochemical properties. The ordered atomic configuration and compositional diversity of HEIs contribute to optimal active‐site isolation, broad tunability of catalytic activity, and remarkable electrochemical stability. These advantages have enabled HEIs to achieve exceptional catalytic performance in various energy‐related applications, positioning them as promising candidates for next‐generation catalytic materials. However, comprehensive reviews on HEIs are scarce. This work provides a systematic overview of recent advances in HEIs research, encompassing innovative synthesis strategies, advanced characterization techniques, and catalytic applications such as the oxygen reduction reaction, hydrogen evolution reaction, electrochemical nitrate reduction reaction, and small‐molecule oxidation reactions. Furthermore, the unique catalytic properties of HEIs are thoroughly elucidated, while discussing the challenges and future research opportunities for HEI‐based catalysts. This work highlights the transformative potential of HEIs in driving the development of energy‐related catalytic technologies and provides valuable insights for designing next‐generation high‐performance catalysts.

Electrochemical carbon dioxide reduction reaction (CO 2 RR) represents an electrochemical process that efficiently converts CO 2 into value‐added products, which hold significant environmental and social importance. Bismuth‐based catalysts have emerged as the primary focus in electrocatalytic research for CO 2 conversion into formic acid, owing to their exceptional catalytic performance and selectivity. By strategically doping heterogeneous atoms, the catalytic activity and stability of bismuth‐based catalysts can be significantly improved. However, research in this field is still in its infancy, with relatively few comprehensive review articles available. Herein, we present a comprehensive review of the progress in heteroatom‐doped bismuth‐based catalysts for CO 2 RR toward formic acid production. Initially, this review outlines the market application prospects of bismuth‐based catalysts, the reduction reaction mechanisms, and various modification methods. Furthermore, it systematically summarizes the latest advancements in heteroatom‐doped bismuth‐based catalysts, including non‐metal atom‐doped bismuth (such as S, F, and Te) and metal atom‐doped bismuth (such as Cu, Co, and Sn). Finally, the review explores the future prospects and challenges associated with the development of heterogeneous atom‐doped Bi‐based catalysts. This review provides deeper insights into accelerating the technologies of CO 2 RR to value‐added formic acid formation using Bi‐based catalysts.

The synthesis and exceptional catalytic performance of nestlike hollow hierarchical MCM-22 microspheres (MCM-22-HS) were presented. The MCM-22-HSs were obtained by one-pot rotating hydrothermal synthesis using carbon black as a hard template via self-assembly combined hydrothermal crystallization. The shell of MCM-22-HS was hierarchically constructed by many flaky MCM-22 crystals. The Mo/MCM-22-HS exhibited significantly improved methane conversion, yield of benzene product and catalyst lifetime for methane dehydroaromatization as a model reaction. The exceptional catalytic performance was attributed to the hollow and hierarchical structure. Faster transfer of Mo species because of the existing mesopores and higher dispersion of Mo species brought by the higher external surface of the Mo/HMCM-22-HS lead to generation of more catalysis active sites and high benzene yield. The sites associated with catalyst deactivation could also be reduced, contributing to improvement of the catalyst lifetime. Both the hierarchical and hollow structure is favorable for the diffusion of larger molecule product, probably contributing to significant improvement of the catalyst lifetime. This work demonstrated the potential applications of hollow hierarchical microsphere structure in catalytic engineering.