Suppression of CO by-production in steam reforming of methanol by addition of zinc oxide to silica-supported copper catalyst

Methanol steam reforming to hydrogen and carbon dioxide is catalyzed over 30 wt% Cu/SiO2 prepared by a sol−gel method. The addition of zinc ions to the starting material of the catalyst results in the suppression of CO formation in the reaction. Zinc oxide is highly dispersed in the catalyst even if the content is as high as 10 wt%. In the catalyst reduced with hydrogen, large Cu particles coexist with fine Cu particles which are oxidized to Cu2O during the reaction. It is estimated that zinc oxide interacts with these Cu particles and stabilizes Cu+ species formed during the reaction.