Methanol Steam Reforming for Hydrogen Production over CuZnZrOx: Promotion Effect of Cu

Mixed metal oxides catalyze steam reforming of methanol (SRM) usually at reaction temperatures of >400 °C, leading to high energy consumption. Herein, we report that a small amount of Cu doping can greatly promote the activity of ZnZrOx in the SRM at low temperatures. The 2%CuZnZrOx can efficiently catalyze the SRM at temperatures as low as 300 °C to give 95.3% methanol conversion, but ZnZrOx only shows low methanol conversion (23.6%) under similar reaction conditions. Structural characterizations show that CuZnZrOx catalysts are ternary solid solutions rich in Ov, which is favorable for water activation. CuZnZrOx with low-valence Cuδ+ shows faster kinetics for the generation and decomposition of HCOOH intermediate than ZnZrOx. The co-presence of Cuδ+ and Ov contributes to the excellent performance of CuZnZrOx. These findings provide an efficient strategy for promoting the catalytic performance of metal oxides toward SRM.