Revealing electric field on low temperature ammonia decomposition activity over ceria-supported catalyst

Abstract

Ammonia decomposition is a promising strategy to address critical challenges in hydrogen storage and transportation, thereby facilitating the widespread adoption of fuel-cell technologies. However, conventional catalytic require harsh conditions (600 °C) for complete conversion. In this study, we report nanocluster Ru/CeO₂ and Ni/CeO₂ catalysts integrated with electric field-assisted catalysis to achieve efficient ammonia decomposition under significantly milder conditions (≤400 °C). With electric field, Ru/CeO₂ and Ni/CeO₂ achieve 100 % and 60 % conversion at 400 °C, and maintain 62 % and 15 % conversion even at 150 °C accompanied by substantial reductions in activation energy (79.5 % and 78.9 %, respectively). Long-term stability tests reveal minimal activity loss (<3 %) over 48 h. Mechanistic studies show that the electric field promotes the formation of Ru-O-Ce bonds, thereby enhancing the strong metal-support interaction (SMSI). This facilitates electron transfer from CeO₂ to the metal site, enhancing NH₃ adsorption and activation, while weakening the interaction between metal and N to promote N₂ desorption. Additionally, electric field-induced proton hopping accelerates hydrogen spillover and suppresses hydrogen poisoning. This work provides a new approach for low temperature, high efficiency ammonia decomposition, offering a viable path for next-generation hydrogen energy infrastructure.