Electrochemical Ammonia Oxidation Reaction on Nickel‐Based Non‐Noble Metal Electrocatalysts: From Mechanistic Understanding to Practical Applications

Abstract

Ammonia stands as a globally vital chemical compound, with the electrochemical ammonia oxidation reaction (AOR) serving as a cornerstone for advancing the ammonia economy. This reaction facilitates both energy and chemical production while contributing to environmental preservation. Recent years have witnessed significant progress in developing AOR catalysts, where platinum‐based materials remain the benchmark. Nevertheless, the scarcity and extremely high cost of platinum pose substantial barriers to widespread commercial adoption. In this context, nickel‐based materials have emerged as highly attractive alternatives, demonstrating considerable promise through notable achievements. In this review, a comprehensive overview is provided for Ni‐based AOR electrocatalysts with potential for practical applications. First, the fundamental mechanisms of the AOR and its practical implementations, including direct ammonia fuel cells and wastewater treatment are discussed. Subsequently, various types of developed Ni‐based catalysts are summarized, highlighting material innovations and performance enhancements. Finally, current technological limitations and outline promising research directions are highlighted. By bridging fundamental mechanisms with engineering requirements, this work offers valuable insights and design principles for developing next‐generation AOR catalysts tailored to specific applications, while suggesting novel implementations of ammonia electrooxidation technology.