Mesoporous Ru/MgO prepared by a deposition-precipitation method as highly active catalyst for producing COx-free hydrogen from ammonia decomposition

Development of highly active catalyst for producing COx-free H2 from ammonia decomposition is critical for the utilization of ammonia as H2 carrier in proton exchange membrane fuel cell. Here, we present a deposition–precipitation (DP) method towards the synthesis of a highly active and stable mesoporous Ru/MgO catalyst for NH3 decomposition reaction. Nitrogen sorption measurements show that the deposition–precipitation method can introduce mesoporosity into the Ru/MgO-DP catalysts. Much enhanced Ru dispersion can be observed for the mesoporous Ru/MgO-DP catalysts in comparison with that of the Ru/MgO catalysts prepared by impregnation method due to the high surface area and plenty of mesopores of the Ru/MgO-DP catalysts. As a result, the mesoporous Ru/MgO-DP catalysts show significantly improved catalytic activity for NH3 decomposition. The activity of Ru/MgO-DP catalyst can be further remarkable enhanced with KOH, which can give comparable catalytic performance with that of the most efficient carbon nanotube supported Ru catalyst.