Plasma‐assisted ammonia decomposition over Fe–Ni alloy catalysts for COx‐Free hydrogen

Abstract

On‐site ammonia (NH3) decomposition is considered as a potential path to supply CO x‐free hydrogen for fuel cell vehicles. In this article, monometallic catalysts (Fe, Co, Ni, and Mo) and bimetallic catalysts (Fe–Co, Mo–Co, Fe–Ni, and Mo–Ni) were prepared and tested in plasma‐catalytic NH3 decomposition, where 6Fe–4Ni catalyst exhibited the highest activity and synergistic capability with plasma. At 500°C, NH3 were completely decomposed (>99.9% NH3 conversion); the rate of H2 production and the energy consumption of H2 production reached 0.96 mol g−1 h−1 and 0.050 kW h (mol g−1)−1, respectively. The 200 h continuous operation results indicate an excellent durability of 6Fe–4Ni catalyst. The catalysts characterization and plasma diagnosis results indicate that NH3 was pre‐activated by plasma into excited‐state species (NH3, ˙NH2, and ˙NH), and the 6Fe–4Ni catalyst exhibited the highest capability to adsorb excited NH3, ˙NH2, and ˙NH species, which could be the main reason why 6Fe–4Ni catalyst exhibited the highest activity. © 2018 American Institute of Chemical Engineers AIChE J, 65: 691–701, 2019