Ce0.6Zr0.3Y0.1O2 solid solutions-supported NiCo bimetal nanocatalysts for NH3 decomposition

Ammonia has become an attractive source for CO_x-free hydrogen production for fuel cell applications. The catalytic performance of Ce_0.6Zr_0.3Y_0.1O₂ solid solutions supported Ni, Co and NiCo bimetallic catalysts are evaluated in the temperature range of 300–600 °C at atmospheric pressure. Due to the synergistic effect between Ni and Co, CZY supported NiCo bimetallic catalysts show higher ammonia decomposition activity compared to Ni or Co monometallic samples. The NiCo bimetallic catalyst with the Ni/Co mass ratio of 1/9 exhibits the highest NH₃ conversion with the GHSV of 6000 mL h⁻¹ g_cat⁻¹, which reaches 100% conversion at 600 °C. Moreover, the Ni₁Co₉/CZY catalyst shows good thermal stability during the 72 h reaction time. The Ni₁Co₉/CZY have the highest total H₂-uptake of 0.35 mmol‧g⁻¹ and the highest TOF_H2 value (40.57 min⁻¹) at 350 °C among all the catalysts. Our characterization confirms the formation of NiCo alloy is responsible for the high activity of Ni₁Co₉/CZY catalyst for the ammonia decomposition.