Plasma-assisted low temperature ammonia decomposition on 3d transition metal (Fe, Co and Ni) doped CeO2 catalysts: Synergetic effect of morphology and co-doping

Catalytic ammonia decomposition generating zero‑carbon and high-energy-density hydrogen over low-cost catalysts has been a hot topic. In this study, ceria support with three morphologies including nanocubes (CeO2-C), nanorods (CeO2-R) and nanospheres (CeO2-S) doped 3d transition metal (Fe, Co and Ni) catalysts have been prepared, characterized and used in ammonia decomposition reaction (ADR). With enhanced metal-support interaction, the co-doped bimetal enriches oxygen vacancies and raised [Ce3+] concentrations, facilitating the electrons transfer from the CeO2 support to active metals. The FeCo/CeO2-S catalyst exhibits excellent thermal stability over continues 48 h. In the non-thermal plasma (NTP) assisted-catalysis in ADR, the FeCo/CeO2-S catalyst showed the highest ammonia conversion with a GHSV of 36,000 mL/gcat/h, which achieves 100% conversion at 550 °C and shows the highest hydrogen generation rate of 29.3 mmol/min·gcat at 500 °C. Our work adopts a novel strategy to improve reaction efficiency of ADR through synergistic promotion of plasma and inexpensive ceria-based catalysts.