Effect of hetero-cation doping on Ru/CeO2 for ammonia decomposition at low temperature in an electric field

Abstract Ammonia is attracting attention as a carbon-free hydrogen carrier with high hydrogen content and good handling properties, although its endothermic decomposition requires high temperatures (>773 K). We previously achieved nearly complete ammonia conversion even at 398 K via an electric field (EF)-assisted catalytic reaction, in which hydrogen conduction on the catalyst surface (i.e., surface protonics) plays a key role. This study reveals a clear correlation between the catalyst's hydrogen adsorption capacity and EF-assisted ammonia decomposition activity. Mechanistic analyses suggest that enhanced hydrogen transfer from Ru to a support with high hydrogen adsorption capacity promotes surface proton conduction, thereby improving catalytic activity under an EF.