Product selectivity in multielectron electrocatalytic reactions is crucial to energy conversion efficiency and chemical production. However, a present practical drawback is the limited understanding of actual catalytic active sites. Here, using as a prototype single-atom catalysts (SACs) in acidic oxygen reduction reaction (ORR), we report the structure–property relationship of catalysts and show for the first time that molecular-level local structure, including first and second coordination spheres (CSs), rather than individual active atoms, synergistically determines the electrocatalytic response. ORR selectivity on Co-SACs can be tailored from a four-electron to a two-electron pathway by modifying first (N or/and O coordination) and second (C–O–C groups) CSs. Using combined theoretical predictions and experiments, including X-ray absorption fine structure analyses and in situ infrared spectroscopy, we confirm that the unique selectivity change originates from the structure-dependent shift of active sites from the center Co atom to the O-adjacent C atom. We show this optimizes the electronic structure and *OOH adsorption behavior on active sites to give the present “best” activity and selectivity of >95% for acidic H2O2 electrosynthesis.

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Demonstrated here is the correlation between atomic configuration induced electronic density of single‐atom Co active sites and oxygen reduction reaction (ORR) performance by combining density‐functional theory (DFT) calculations and electrochemical analysis. Guided by DFT calculations, a MOF‐derived Co single‐atom catalyst with the optimal Co1‐N3PS active moiety incorporated in a hollow carbon polyhedron (Co1‐N3PS/HC) was designed and synthesized. Co1‐N3PS/HC exhibits outstanding alkaline ORR activity with a half‐wave potential of 0.920 V and superior ORR kinetics with record‐level kinetic current density and an ultralow Tafel slope of 31 mV dec−1, exceeding that of Pt/C and almost all non‐precious ORR electrocatalysts. In acidic media the ORR kinetics of Co1‐N3PS/HC still surpasses that of Pt/C. This work offers atomic‐level insight into the relationship between electronic density of the active site and catalytic properties, promoting rational design of efficient catalysts.

By the in situ X-ray absorption results, the gradually decrease of Cu oxidation state under applied potential implied that low-valence Cu (+1) species in the atomic interface of Cu–N4–C8S2 may work as the catalytic sites during an ORR process.

Single-atom catalysts (SACs) maximize the utility efficiency of metal atoms and offer great potential for hydrogen evolution reaction (HER). Bimetal atom catalysts are an appealing strategy in virtue of the synergistic interaction of neighboring metal atoms, which can further improve the intrinsic HER activity beyond SACs. However, the rational design of these systems remains conceptually challenging and requires in-depth research both experimentally and theoretically. Here, we develop a dual-atom catalyst (DAC) consisting of O-coordinated W-Mo heterodimer embedded in N-doped graphene (W1Mo1-NG), which is synthesized by controllable self-assembly and nitridation processes. In W1Mo1-NG, the O-bridged W-Mo atoms are anchored in NG vacancies through oxygen atoms with W─O─Mo─O─C configuration, resulting in stable and finely distribution. The W1Mo1-NG DAC enables Pt-like activity and ultrahigh stability for HER in pH-universal electrolyte. The electron delocalization of W─O─Mo─O─C configuration provides optimal adsorption strength of H and boosts the HER kinetics, thereby notably promoting the intrinsic activity.

Main group antimony (Sb) species are promising electrocatalysts that promote CO2 reduction reaction (CO2RR) to formate, which is an important hydrogen storage material and a key chemical intermediate in many...

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.

The electrochemical hydrogen evolution reaction (HER) in alkaline medium is of great significance for the conversion of renewable energy into hydrogen fuel. Most catalysts exhibit limited HER performance in alkaline electrolytes due to the inefficient dissociation of water to initiate the Volmer reaction. Herein, we report the atomically dispersed tungsten (W)optimized MoP nanoparticles on N,P-doped graphene oxide (W 0.25 Mo 0.75 P/ PNC) that possesses high activity with impressively low overpotentials (η = 70 mV@10 mA cm −2 , η = 49 mV@10 mA mg cat. −1) in alkaline medium. The catalyst features with the atomically isolated W atoms that can optimize the surface electronic structure by occupying the vacant Mo sites in the MoP lattice, corroborated by the X-ray absorption spectra, further leading to moderate hydrogen adsorption energy on the surface. The first-principles computation reveals that the atomically dispersed W atoms effectively reduce the water dissociation energy and facilitate the adsorption kinetics, leading to high activity. This work proposes an elegant design principle based on the pseudo-single-atom strategy to facilitate hydrogen electrocatalysis.