Electrocatalytic NO reduction reaction to generate NH3 under ambient conditions offers an attractive alternative to the energy-extensive Haber–Bosch route; however, the challenge still lies in the development of cost-effective and high-performance electrocatalysts. Herein, nanoporous VN film is first designed as a highly selective and stable electrocatalyst for catalyzing reduction of NO to NH3 with a maximal Faradaic efficiency of 85% and a peak yield rate of 1.05 × 10–7 mol·cm–2·s–1 (corresponding to 5,140.8 μg·h–1·mgcat.–1) at –0.6 V vs. reversible hydrogen electrode in acid medium. Meanwhile, this catalyst maintains an excellent activity with negligible current density and NH3 yield rate decays over 40 h. Moreover, as a proof-of-concept of Zn–NO battery, it delivers a high power density of 2.0 mW·cm–2 and a large NH3 yield rate of 0.22 × 10–7 mol·cm–2·s–1 (corresponding to 1,077.1 μg·h–1·mgcat.–1), both of which are comparable to the best-reported results. Theoretical analyses confirm that the VN surface favors the activation and hydrogenation of NO by suppressing the hydrogen evolution. This work highlights that the electrochemical NO reduction is an eco-friendly and energy-efficient strategy to produce NH3.

High-efficiency electrocatalytic NO reduction to NH
 3 by nanoporous VN

Electrochemical CO2 reduction has attracted much attention due to its advantages to convert CO2 gas into useful chemicals and fuels. Herein, we have developed prism-shaped Cu catalysts for efficient and stable CO2 electrore-duction by using an electrodeposition method. These Cu prism electrodes were characterized by scanning electron mi-croscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. Electrochemical CO2 reduction measurements show improved activities for C2H4 production with high partial current density of -11.8 mA/cm2, which is over four times higher than that of the planar Cu sample (-2.8 mA/cm2). We have demonstrated that the enhanced C2H4 production is partially attributed to the higher density of defect sites available on the roughened Cu prism surface. Furthermore, stability tests show a drastic improvement in maintaining C2H4 production over 12 hours. The enhanced performance and durability of prism Cu catalysts hold promise for future industrial applications.

/pdf/prism-shaped-cu-nanocatalysts-for-electrochemical-co2-3jd6dinm1n.pdf

Prism-Shaped cu Nanocatalysts for Electrochemical Co2 Reduction to Ethylene

Given the simultaneous presence of two metal active centres, some special interactions occur between active sites in diatomic catalysts (DACs). Such interactions play an important role in determining the rate and selectivity of the reaction, denoted as long-range interaction (LRI). The right combination must be screened and clarified to achieve the targeted efficiency. To date, various types of DACs have been synthesised and applied in electrochemistry. However, the LRI has not been systematically summarised. Herein, the regulation, mechanism and electrocatalytic applications of LRI are comprehensively summarised and discussed. In addition to the basic information above, the challenges, opportunities, and future development of LRI on DACs are proposed to present an overall view and reference for future research.

Long-Range Interaction on Diatomic Catalysts Boosting Electrocatalysis.

Polycrystalline SnSx nanofilm enables CO2 electroreduction to formate with high current density.

NiFe layered double hydroxide nanosheet array for high-efficiency electrocatalytic reduction of nitric oxide to ammonia.

Defect engineering is an effective strategy to improve the activity of two-dimensional molybdenum disulfide base planes toward electrocatalytic hydrogen evolution reaction. Here, we report a Frenkel-defected monolayer MoS2 catalyst, in which a fraction of Mo atoms in MoS2 spontaneously leave their places in the lattice, creating vacancies and becoming interstitials by lodging in nearby locations. Unique charge distributions are introduced in the MoS2 surface planes, and those interstitial Mo atoms are more conducive to H adsorption, thus greatly promoting the HER activity of monolayer MoS2 base planes. At the current density of 10 mA cm-2, the optimal Frenkel-defected monolayer MoS2 exhibits a lower overpotential (164 mV) than either pristine monolayer MoS2 surface plane (358 mV) or Pt-single-atom doped MoS2 (211 mV). This work provides insights into the structure-property relationship of point-defected MoS2 and highlights the advantages of Frenkel defects in tuning the catalytic performance of MoS2 materials. 

/pdf/frenkel-defected-monolayer-mos2-catalysts-for-efficient-1qaxzvfq.pdf

Frenkel-defected monolayer MoS2 catalysts for efficient hydrogen evolution

Coordination Environment Engineering to Boost Electrocatalytic CO2 Reduction Performance by Introducing Boron into Single-Fe-Atomic Catalyst

Rechargeable aqueous Zn–CO2 batteries show great promise in meeting severe environmental problems and energy crises due to their combination of CO2 utilization and energy output, as well as advantages of high theoretical energy density, abundant raw materials, and high safety. Developing high‐efficiency and stable CO2 reduction reaction (CO2RR) electrocatalysts is of critical importance for the promotion of this technology. Atomically dispersed metal‐based catalysts (ADMCs), with extremely high atom‐utilization efficiency, tunable coordination environments, and superior intrinsic catalytic activity, are emerging as promising candidates for Zn–CO2 batteries. Herein, some recent developments in atomically dispersed metal‐based catalysts for Zn–CO2 batteries are summarized, including transition metal and non‐transition metal sites. Moreover, various synthetic strategies, characterization methods, and the relationship between active site structures and CO2RR activity/Zn–CO2 battery performance are introduced. Finally, some challenges and perspectives are also proposed for the future development of ADMCs in Zn–CO2 batteries.

Atomically Dispersed Metal‐Based Catalysts for Zn–CO2 Batteries

Anion exchange membrane fuel cells are limited by the slow kinetics of alkaline hydrogen oxidation reaction (HOR). Here, we establish HOR catalytic activities of single-atom and diatomic sites as a function of *H and *OH binding energies to screen the optimal active sites for the HOR. As a result, the Ru-Ni diatomic one is identified as the best active center. Guided by the theoretical finding, we subsequently synthesize a catalyst with Ru-Ni diatomic sites supported on N-doped porous carbon, which exhibits excellent catalytic activity, CO tolerance, and stability for alkaline HOR and is also superior to single-site counterparts. In situ scanning electrochemical microscopy study validates the HOR activity resulting from the Ru-Ni diatomic sites. Furthermore, in situ x-ray absorption spectroscopy and computational studies unveil a synergistic interaction between Ru and Ni to promote the molecular H2 dissociation and strengthen OH adsorption at the diatomic sites, and thus enhance the kinetics of HOR.

/pdf/design-of-ru-ni-diatomic-sites-for-efficient-alkaline-1elqgsct.pdf

Jun-Tao Luo

Papers

Polycrystalline SnSx nanofilm enables CO2 electroreduction to formate with high current density.

Frenkel-defected monolayer MoS2 catalysts for efficient hydrogen evolution

Coordination Environment Engineering to Boost Electrocatalytic CO2 Reduction Performance by Introducing Boron into Single-Fe-Atomic Catalyst

Atomically Dispersed Metal‐Based Catalysts for Zn–CO2 Batteries

Design of Ru-Ni diatomic sites for efficient alkaline hydrogen oxidation