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The strong metal–support interactions (SMSI) between metal and its support have been regarded as a valid approach to enhance the catalytic performance; however, the extent to which exploration of electronic state regulation affects catalytic performance of alcohol oxidation reactions (AOR) has been rarely reported. In this paper, PdAg nanoparticles loaded on a N-doped carbon substrate with controlled nitrogen content (PdAg@NxC, x representing the nitrogen contents) was synthesized through a seeded synthesis strategy for alkaline AOR. Results show that the electronic state of PdAg nanoparticles was significantly modified after nitrogen doping in the carbon support. Experimental and theoretical results indicate that with increasing nitrogen content, the degree of electronic state regulation becomes increasingly significant. Density functional theory (DFT) calculations suggest that the increased degree of SMSI promotes OH* adsorption on the PdAg surface and weakens the binding between catalyst and CO*. As a result, the PdAg@N15.3C with the highest N content exhibits excellent AOR performance, achieving a MA/SA of 10.8 A mgPd−1/13.2 mA cm−2 and 3.8 A mgPd−1/4.7 mA cm−2 on the EOR and MOR, respectively. Moreover, due to the changes in the adsorption energy of key intermediates on PdAg nanoparticles, the onset oxidation potential of PdAg@N15.3C shows a negative shift of 180 mV compared to PdAg@C as revealed by CO stripping analysis, signifying an increase in the CO tolerance. Our study demonstrates the influence of the SMSI effect between the active center and the support on the catalytic performance for AOR and presents a pathway to achieve high AOR performance through SMSI engineering. [ABSTRACT FROM AUTHOR]

Herein, we report a facile strategy for constructing hybrid coordination configurations by combining functionalized graphene quantum dots (GQDs) with CoPc (CoPc/R-GQDs, with R being –NH2 or –OH) for electrochemical CO2 reduction. Benefiting from the high density of functional groups that can be provided by GQDs and the strong electron-donating property of –NH2, the examined CoPc/NH2-GQDs achieved a 100% faradaic efficiency for CO formation (FECO) at −0.8 to −0.9 V vs. RHE, and high FECO (over 90%) over a wide potential range of 500 mV. This work has presented a novel approach for catalyst design, specifically involving molecular engineering of quantum dots, which can also be applied to other essential electrochemical reactions. [ABSTRACT FROM AUTHOR]

Electrochemical conversion of NO3− to NH3 production is of great environmental significance for water pollution treatment and can artificially close the nitrogen cycle. However, direct nine protons and eight electrons transfer lead to low Faraday efficiency (FE) and yield. Herein, the single copper site immobilized on N,P co‐doped carbon substrates (Cu−N4/P) was prepared for efficient NO3−‐to‐NH3 conversion. Benefiting from the electronic redistribution of the Cu site induced by the introduction of the less electronegative element P, the Cu−N4/P catalyst exhibited a high Faraday efficiency of FE (95.89 %) for NH3 product formation at a potential of −0.6 V vs. RHE and 100 % conversion of NO3−−N was achieved after 5 hours of electrolysis. Density functional theory (DFT) explains the effective operation mechanism that P doping can promote the spontaneous hydrogenation of *NO to form *NOH, thus promoting the formation of NH3 from NO3− reduction reaction. The heteroatom doping strategy mentioned proposes a new approach for promoting NO3−‐to‐NH3 conversion at atomic level catalytic sites. [ABSTRACT FROM AUTHOR]

The precise coordination environment manipulation and interfacial electron redistribution are significant strategies for the modulation of electronic configuration and intermediates adsorption behaviors, while the complex synergistic effect is yet to materialize due to the lack of catalyst platform. Herein, an atomic‐scale catalyst platform containing single Cu site with tunable coordination environment (Cu‐N4 or Cu‐S1N3) and easy decoration of Cu cluster (Cux) for electrochemical O2 reduction reaction (ORR) is reported. Theoretical analysis shows that the charge redistribution and up‐shifting d‐band center of single Cu site induced by the asymmetrical coordination environment and Cux effectively strength *OOH adsorption. The modulation in intermediates adsorption enables Cu‐S1N3/Cux a superior ORR performance compared with the samples without S atom and/or Cux. Moreover, the adsorption behavior of *OOH and d‐band center of single Cu site tuned by coordination environment and interfacial interactions are correlated linearly with catalytic potential, e.g., half‐wave potential and reaction kinetic, e.g., Tafel slope for ORR, indicating the high applicability of the intermediate adsorption strength and d‐band center as the indicators for catalytic performance. This study provides a comprehensive modulation strategy for electron configuration and intermediates adsorption behaviors, and can be extended to facilitate other proton‐coupled electron transfer reactions. [ABSTRACT FROM AUTHOR]

Powered by clean and renewable energy, electrocatalytic CO2 reduction reaction (CO2RR) to chemical feedstocks is an effective way to mitigate the greenhouse effect and artificially close the carbon cycle. However, the performance of electrocatalytic CO2RR was impeded by the strong thermodynamic stability of CO2 molecules and the high susceptibility to hydrogen evolution reaction (HER) in aqueous phase systems. Moreover, the numerous reaction intermediates formed at very near potentials lead to poor selectivity of reaction products, further preventing the industrialization of CO2RR. Catalysis in confined space can enrich the reaction intermediates to improve their coverage at the active site, increase local pH to inhibit HER, and accelerate the mass transfer rate of reactants/products and subsequently facilitate CO2RR performance. Therefore, we summarize the research progress on the application of the confinement effects in the direction of CO2RR in theoretical and experimental directions. We first analyzed the mechanism of the confinement effect. Subsequently, the confinement effect was discussed in various forms, which can be characterized as an abnormal catalytic phenomenon due to the relative limitation of the reaction region. In specific, based on the physical structure of the catalyst, the confinement effect was divided in four categories: pore structure confinement, cavity structure confinement, active center confinement, and other confinement methods. Based on these discussions, we also have summarized the prospects and challenges in this field. This review aims to stimulate greater interests for the development of more efficient confined strategy for CO2RR in the future. [ABSTRACT FROM AUTHOR]

Developing bifunctional catalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is essential for the development of zinc–air batteries (ZABs), but several challenges remain in terms of bifunctional activity. FeCo2S4/N-S-rGO was prepared by in situ homogeneous growth of bimetallic sulfide FeCo2S4 on N, S-doped reduced graphene oxide. FeCo2S4/N-S-rGO exhibits a half-wave potential of 0.89 V for ORR and an overpotential of 0.26 V at 10 mA cm−2 for OER, showing significantly bifunctional activity superior to Pt/C (0.85 V) and RuO2 (0.41 V). Moreover, the FeCo2S4/N-S-rGO assembled ZAB shows a superior specific capacity and a power density of 259.13 mW cm−2. It is demonstrated that the interfacial electron redistribution between FeCo2S4 nanoparticles and heteroatom-doped rGO matrix can efficiently improve the electrochemical performance of the catalyst. The results provide new insights into the preparation of high-capability composite catalysts combining transition metal sulfides with carbon materials for applications in ZABs. [ABSTRACT FROM AUTHOR]