High-performance htlcs-derived cuznal catalysts for hydrogen production via methanol steam reforming

A series of CuZnAl oxide-composite catalysts were prepared via decomposition of CuZnAl hydrotalcite-like compounds (HTLcs). The catalysts derived from CuZnAl HTLcs (Cu: 37%, Zn: 15%, Al: 48% mol; using metal nitrate or acetate precursors) at 600°C provided excellent activity and stability for the methanol steam reforming. CuZnAI HTLcs were almost decomposed completely at 600°C to form highly dispersed CuO with large specific surface area while forming CUAI₂O₄ spinel that played a key role in separating and stabilizing the nano-sized Cu and ZnO during the reaction. The CuZnAI catalyst prepared from metal acetates could highly convert H ₂O/MeOH (1.3/1, mollmol) mixture into hydrogen with only ∼0.05% CO at 250°C or ∼0.005% at 210°C. It is evidenced that the former afforded stronger Cu-ZnO interaction, which might be the intrinsic reason for the significant promotion of catalyst selectivity.