The interfacial association dehydrogenation mechanism guides the design of anode Pt-Based catalysts for direct ammonia fuel cells: A perspective

• This paper reviews the O-S and G-M ammonia oxidation mechanisms in alkaline direct ammonia fuel cell anodes. • It explores recent support-regulation strategies leveraging active site-support interactions for Pt-based catalysts. • Analyzed the optimization strategies of enhancing Pt activity through metal doping to adjust the electronic structure. • Discussed strategies for optimizing species transport on catalyst surfaces to enhance efficiency/selectivity. • Future directions are proposed, including advanced catalysts, membrane innovations, system integration, among others. Direct ammonia fuel cells (DAFCs), as a new eco-friendly energy conversion technology, show promise for ammonia energy utilization, potentially replacing traditional hydrogen fuel cells. However, their development is hindered by the sluggish ammonia oxidation reaction (AOR) at the anode. Strategies to enhance AOR kinetics for higher energy conversion efficiency remain limited. Given the complex interface processes and electron transfers involved, analyzing and summarizing existing strategies to improve AOR is crucial from a mechanistic perspective. In this context, a systematic overview of the common Gerischer-Mauerer (G-M) mechanism, which is also known as associative dehydrogenation mechanism in AOR processes is presented. Modification strategies reported for platinum-based catalysts are categorized based on the rate-determining steps in the dehydrogenation process: enhancing carrier-catalyst interaction to improve catalyst dispersion and shape, thereby regulating active sites on the catalyst surface; effectively adjusting the platinum surface electronic structure through synergistic interactions with different metal atoms to optimize reactant adsorption energy; and optimizing material transport channels of reaction intermediates by adjusting catalyst surface interface properties to enhance electrocatalytic efficiency. Finally, the development of AOR catalysts and DAFCs is structurally guided to accelerate the AOR and improve the fuel cell performance of DAFCs, with the aim of enabling the commercial application of DAFCs in daily life.