Interface Engineering of PtZn Alloy and Nb₂O₅ for Promoting Ammonia Oxidation Reaction and Hydrogen Evolution Reaction

Abstract

Ammonia electrolysis is a promising technology to obtain green hydrogen with zero-carbon emission, in which ammonia oxidation reaction (AOR) and hydrogen evolution reaction (HER) occur at the anode and cathode, respectively. However, the lack of efficient catalysts hinders its practical application. Herein, PtZn alloy is combined with Nb 2 O 5 to construct a bifunctional heterostructure catalyst (PtZn-Nb 2 O 5 /C). The optimal sample with Nb 2 O 5 content of 7.05 wt % demonstrates the best performance with a peak current density of 304.1 mA mg −1 Pt for AOR, and it is only reduced by 17.0% after 4000 cycles of durability tests. For HER, it has a low overpotential of 34 mV at −10 mA cm −2 under the alkaline condition. This can be ascribed to the interfacial interaction between the PtZn alloy and Nb 2 O 5 , which adjusts the adsorption behavior of OH ad to concurrently promote AOR and HER activity. This work thus proposes a viable strategy to design an efficient bifunctional catalyst for hydrogen generation from ammonia electrolysis.

Platinum Cluster Decoration on Hollow Carbon Spheres for High-Efficiency Hydrogen Evolution Reaction

“…As an ideal zero-carbon energy carrier, hydrogen has a strategic position in developing alternatives to fossil fuels for the future of humanity. − In order to lower the overpotential and increase the energy conversion efficiency, high-efficiency electrocatalysts are required for the sustainable and vital technology of renewable energy-driven water electrolysis for the production of high-purity hydrogen. − For the hydrogen evolution reaction (HER), Pt-based materials continue to be the highest-efficiency electrocatalysts. , However, the high cost and rarity hinder their large-scale application. − At present, diminishing the scale of Pt to atomic clusters (ACs) or single atoms (SAs) on a substrate is an accessible strategy to greatly lower the cost of Pt-based electrocatalysts and optimize their superior selectivity and catalytic activity. − Furthermore, the morphology and microstructure of the electrocatalysts can influence their catalytic performances for HER. Hence, exploiting the desired substrates is enormously challenging but desirable to develop Pt-based electrocatalysts with high intrinsic activity.…”