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Rational design and construction of low-cost and highly efficient electrocatalysts for hydrogen evolution reaction (HER) is meaningful but challenging. Herein, a robust three dimensional (3D) hollow CoSe2@ultrathin MoSe2 core@shell heterostructure (CoSe2@MoSe2) is proposed as an efficient HER electrocatalyst through interfacial engineering. Benefitting from the abundant heterogeneous interfaces on CoSe2@MoSe2, the exposed edge active sites are maximized and the charge transfer at the hetero-interfaces is accelerated, thus facilitating the HER kinetics. It exhibits remarkable performance in pH-universal conditions. Notably, it only needs an overpotential (η10) of 108 mV to reach a current density of 10 mA·cm−2 in 1.0 M KOH, outperforming most of the reported transition metal selenides electrocatalysts. Density functional theory (DFT) calculations unveil that the heterointerfaces synergistically optimize the Gibbs free energies of H2O and H* during alkaline HER, accelerating the reaction kinetics. The present work may provide new construction guidance for rational design of high-efficient electrocatalysts. [ABSTRACT FROM AUTHOR]

Copper-based materials can reliably convert carbon dioxide into multi-carbon products but they suffer from poor activity and product selectivity. The atomic structure-activity relationship of electrocatalysts for the selectivity is controversial due to the lacking of systemic multiple dimensions for operando condition study. Herein, we synthesized high-performance CO2RR catalyst comprising of CuO clusters supported on N-doped carbon nanosheets, which exhibited high C2+ products Faradaic efficiency of 73% including decent ethanol selectivity of 51% with a partial current density of 14.4 mA/cm−2 at −1.1 V vs. RHE. We evidenced catalyst restructuring and tracked the variation of the active states under reaction conditions, presenting the atomic structure-activity relationship of this catalyst. Operando XAS, XANES simulations and Quasi-in-situ XPS analyses identified a reversible potential-dependent transformation from dispersed CuO clusters to Cu2-CuN3 clusters which are the optimal sites. This cluster can't exist without the applied potential. The N-doping dispersed the reduced Cun clusters uniformly and maintained excellent stability and high activity with adjusting the charge distribution between the Cu atoms and N-doped carbon interface. By combining Operando FTIR and DFT calculations, it was recognized that the Cu2-CuN3 clusters displayed charge-asymmetric sites which were intensified by CH3* adsorbing, beneficial to the formation of the high-efficiency asymmetric ethanol. Copper-based materials can convert carbon dioxide into multi-carbon products but suffer from poor activity and selectivity. Here, the authors report CuO clusters supported on nitrogen-doped carbon nanosheets for the reduction CO2-to-ethanol, and investigate the change in the catalytic sites while in operation. [ABSTRACT FROM AUTHOR]

Main‐group element indium (In) is a promising electrocatalyst which triggers CO2 reduction to formate, while the high overpotential and low Faradaic efficiency (FE) hinder its practical application. Herein, we rationally design a new In single‐atom catalyst containing exclusive isolated Inδ+–N4 atomic interface sites for CO2 electroreduction to formate with high efficiency. This catalyst exhibits an extremely large turnover frequency (TOF) up to 12500 h−1 at −0.95 V versus the reversible hydrogen electrode (RHE), with a FE for formate of 96 % and current density of 8.87 mA cm−2 at low potential of −0.65 V versus RHE. Our findings present a feasible strategy for the accurate regulation of main‐group indium catalysts for CO2 reduction at atomic scale. [ABSTRACT FROM AUTHOR]

Nickel-based catalysts have been regarded as one of the most promising electrocatalysts for urea oxidation reaction (UOR), however, their activity is largely limited by the inevitable self-oxidation reaction of Ni species (NSOR) during the UOR. Here, we proposed an interface chemistry modulation strategy to trigger the occurrence of UOR before the NSOR via constructing a 2D/2D heterostructure that consists of ultrathin NiO anchored Ru-Co dual-atom support (Ru-Co DAS/NiO). Operando spectroscopic characterizations confirm this unique triggering mechanism on the surface of Ru-Co DAS/NiO. Consequently, the fabricated catalyst exhibits outstanding UOR activity with a low potential of 1.288 V at 10 mA cm -2 and remarkable long-term durability for more than 330 h operation. DFT calculations and spectroscopic characterizations demonstrate that the favorable electronic structure induced by this unique heterointerface endows the catalyst energetically more favorable for the UOR than the NSOR., (© 2023 Wiley-VCH GmbH.)

Ruthenium-based materials are considered great promising candidates to replace Pt-based catalysts for hydrogen production in alkaline conditions. Herein, we adopt a facile method to rationally design a neoteric Schottky catalyst in which uniform ultrafine ruthenium nanoparticles featuring lattice compressive stress are supported on nitrogen-modified carbon nanosheets (Ru NPs/NC) for efficient hydrogen evolution reaction (HER). Lattice strain and Schottky junction dual regulation ensures that the Ru NPs/NC catalyst with an appropriate nitrogen content displays superb H 2 evolution in alkaline media. Particularly, Ru NPs/NC-900 with 1.3% lattice compressive strain displays attractive activity and durability for the HER with a low overpotential of 19 mV at 10 mA cm -2 in 1.0 M KOH electrolyte. The in situ X-ray absorption fine structure measurements indicate that the low-valence Ru nanoparticle with shrinking Ru-Ru bond acts as catalytic active site during the HER process. Furthermore, multiple spectroscopy analysis and density functional theory calculations demonstrate that the lattice strain and Schottky junction dual regulation tunes the electron density and hydrogen adsorption of the active center, thus enhancing the HER activity. This strategy provides a novel concept for the design of advanced electrocatalysts for H 2 production.

Main-group element indium (In) is a promising electrocatalyst which triggers CO 2 reduction to formate, while the high overpotential and low Faradaic efficiency (FE) hinder its practical application. Herein, we rationally design a new In single-atom catalyst containing exclusive isolated In δ+ -N 4 atomic interface sites for CO 2 electroreduction to formate with high efficiency. This catalyst exhibits an extremely large turnover frequency (TOF) up to 12500 h -1 at -0.95 V versus the reversible hydrogen electrode (RHE), with a FE for formate of 96 % and current density of 8.87 mA cm -2 at low potential of -0.65 V versus RHE. Our findings present a feasible strategy for the accurate regulation of main-group indium catalysts for CO 2 reduction at atomic scale., (© 2020 Wiley-VCH GmbH.)

Oxygen-involved electrochemical reactions are crucial for plenty of energy conversion techniques. Herein, we rationally designed a carbon-based Mn-N 2 C 2 bifunctional electrocatalyst. It exhibits a half-wave potential of 0.915 V versus reversible hydrogen electrode for oxygen reduction reaction (ORR), and the overpotential is 350 mV at 10 mA cm -2 during oxygen evolution reaction (OER) in alkaline condition. Furthermore, by means of operando X-ray absorption fine structure measurements, we reveal that the bond-length-extended Mn 2+ -N 2 C 2 atomic interface sites act as active centers during the ORR process, while the bond-length-shortened high-valence Mn 4+ -N 2 C 2 moieties serve as the catalytic sites for OER, which is consistent with the density functional theory results. The atomic and electronic synergistic effects for the isolated Mn sites and the carbon support play a critical role to promote the oxygen-involved catalytic performance, by regulating the reaction free energy of intermediate adsorption. Our results give an atomic interface strategy for nonprecious bifunctional single-atom electrocatalysts.

Atomic interface engineering is an effective pathway to regulate the performance of single metal atom catalysts for electrochemical reactions in energy applications. Herein, we construct a sulfur modified Mn-N-C single atom catalyst through a metal-organic framework derived atomic interface strategy, which exhibits outstanding ORR activity with a half-wave potential of 0.916 V vs. RHE in alkaline media. Moreover, operando X-ray absorption spectroscopy analysis indicates that the isolated bond-length extending the low-valence Mn-N 4 -C x S y moiety serves as an active site during the ORR process. These findings suggest a promising method for the advancement of single atom catalysis., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

The engineering coordination environment offers great opportunity in performance tunability of isolated metal single-atom catalysts. For the most popular metal-N x (MN x ) structure, the replacement of N atoms by some other atoms with relatively weak electronegativity has been regarded as a promising strategy for optimizing the coordination environment of an active metal center and promoting its catalytic performance, which is still a challenge. Herein, we proposed a new synthetic strategy of an in situ phosphatizing of triphenylphosphine encapsulated within metal-organic frameworks for designing atomic Co 1 -P 1 N 3 interfacial structure, where a cobalt single atom is costabilized by one P atom and three N atoms (denoted as Co-SA/P-in situ). In the acidic media, the Co-SA/P-in situ catalyst with Co 1 -P 1 N 3 interfacial structure exhibits excellent activity and durability for the hydrogen evolution reaction (HER) with a low overpotential of 98 mV at 10 mA cm -2 and a small Tafel slope of 47 mV dec -1 , which are greatly superior to those of catalyst with Co 1 -N 4 interfacial structure. We discover that the bond-length-extended high-valence Co 1 -P 1 N 3 atomic interface structure plays a crucial role in boosting the HER performance, which is supported by in situ X-ray absorption fine structure (XAFS) measurements and density functional theory (DFT) calculation. We hope this work will promote the development of high performance metal single-atom catalysts.