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 degrees C provided excellent activity and stability for the methanol steam reforming. CuZnAl HTLcs were almost decomposed completely at 600 degrees C to form highly dispersed CuO with large specific surface area while forming CuAl2O4 spinel that played a key role in separating and stabilizing the nano-sized Cu and ZnO during the reaction. The CuZnAl catalyst prepared from metal acetates could highly convert H2O/MeOH (1.3/1, mol/mol) mixture into hydrogen with only similar to 0.05% CO at 250 degrees C or similar to 0.005% at 210 degrees 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. (C) 2009 American Institute of Chemical Engineers AIChE J, 55: 1217-1228, 2009