Carbon-free sustainable energy technology: Electrocatalytic ammonia oxidation reaction

Ammonia is sufficiently advantageous both for hydrogen storage and as a direct fuel cell application. Over the past century, mechanistic and applied research of electrocatalytic ammonia oxidation reaction (AOR) have developed together and promoted each other, yielding considerable results. In this paper, the development of AOR is reviewed, and the research results of its internal reaction mechanism are summarized, providing new references and research directions for future studies. Combining mechanistic analysis and experimental investigation, the problems involved in the application of catalysts for AOR are analyzed at the atomic level. The catalytic properties of precious metal and non-precious metal material systems are compared. The paper outlines the common characteristics of catalysts with good activity. Then a carbon-free sustainable energy network is envisioned around the AOR, which has far-reaching implications for environmental protection and sustainable energy supply. Finally, the methods and means that can improve the catalyst activity are pointed out, providing directions for the design and synthesis of future catalysts for AOR.