Swinging Hydrogen Evolution to Nitrate Reduction Activity in Molybdenum Carbide by Ruthenium Doping

ACS Catalysis, Journal Year: 2022, Volume and Issue: 12(24), P. 15045 - 15055

Published: Nov. 28, 2022

A common challenge for electrochemical ammonia synthesis in an aqueous phase is the consumption of Faradaic charge by competing hydrogen evolution reaction (HER), which reduces efficiency desired conversion, i.e., nitrate reduction (NO3RR) to ammonium. This problem particularly severe when a single-phase catalyst operated at high current limits, thus cocatalyst system that works synergistically acquisition and deoxygenation needed promote NO3RR over HER. Herein, we select well-known HER Mo2C investigate how metal doping can switch its kinetics from HER-dominated NO3RR-dominated pathways. At 3.8 wt % Ru Mo2C, 75% single pass conversion (0.1 M) ammonium 16 cm2 flow electrolyzer was achieved, corresponding yield rate 9.07 mmol h–1 full cell voltage 2 V. As confirmed DFT calculations kinetic isotope experiments, ruthenium dopants matrix serve as sink point adsorbed during cooperative *NO3 *NO2 on Ru–Mo cocatalytic site. Our study suggests optimizing reactions systems effective strategy synthesis.

Language: Английский

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Interfacial built-in electric-field for boosting energy conversion electrocatalysis

Nanoscale Horizons, Journal Year: 2023, Volume and Issue: 8(4), P. 441 - 452

Published: Jan. 1, 2023

A critical review of built-in electric fields for the applications in electrocatalytic reactions is organized by focusing on fundamental concepts, modification strategies, and positive influences promotion catalytic performance.

Language: Английский

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“One Stone Five Birds” Plasma Activation Strategy Synergistic with Ru Single Atoms Doping Boosting the Hydrogen Evolution Performance of Metal Hydroxide

Advanced Functional Materials, Journal Year: 2023, Volume and Issue: 33(25)

Published: March 8, 2023

Abstract Layered metal hydroxides (LMHs) are promising catalysts for oxygen evolution reaction. However, the hydrogen reaction (HER) activity of LMHs is unsatisfactory due to their poor conductivity and limited active sites. Herein, taking Ni(OH) 2 as demonstration, a novel “one stone five birds” plasma activation strategy synergistic with Ru single atoms (Ru SAs) doping developed boost HER by constructing heterostructured β‐Ni(OH) /Ni‐Ru SAs nanosheet arrays (NSAs). Benefiting from structural/compositional features optimized electronic state, as‐obtained NSAs exhibit splendid low overpotential 16 mV at 10 mA cm −2 small Tafel slope 21 dec −1 in alkaline solution. Excellent performance seawater neutral solutions also demonstrated NSAs. The play important roles enhancing water adsorption accelerating kinetics dissociation. Density functional theory (DFT) calculations reveal that introduction system facilitates generation surface OH vacancies providing more sites well decreases antibonding state density generated mid‐gap H strength toward optimal range.

Language: Английский

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Rational Design of Hydrogen Evolution Reaction Electrocatalysts for Commercial Alkaline Water Electrolysis

Small Structures, Journal Year: 2023, Volume and Issue: 4(8)

Published: March 22, 2023

With the further exploitation of renewable energy sources, electrochemical hydrogen evolution reaction (HER) is considered a key technology to solve environmental problems and achieve global carbon neutrality. Currently, alkaline water electrolyzers (AWEs) have been revitalized as traditional electrolytic production industry, yet they face great challenges in achieving new technological breakthroughs due catalytic properties electrode materials. In media, besides slow kinetics oxygen reaction, sluggish HER needing dissociation mass transfer at high current densities are among major factors limiting development electrolysis for industrial applications. Therefore, it importance design electrocatalysts with activity stability (>500 mA cm −2 ) applications “Research Development level” (R&D level). Herein, brief overview AWEs scale presented, some mainstream recognized catalysis mechanisms electrolytes summarized. Based on requirements application theoretical guidance, activation strategies also This review will propose insights into future electrolysis.

Language: Английский

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Reversible hydrogen spillover at the atomic interface for efficient alkaline hydrogen evolution

Energy & Environmental Science, Journal Year: 2024, Volume and Issue: 17(4), P. 1397 - 1406

Published: Jan. 1, 2024

Ru 1 –Mo 2 C, a novel dual-site synergistic catalyst, demonstrated exceptional performance for the alkaline hydrogen evolution reaction (HER) through reversible spillover mechanism.

Language: Английский

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