Study on factors controlling catalytic activity for low-temperature water-gas-shift reaction on Cu-based catalysts

Influence of metal oxide added to Cu catalysts on the catalytic activity of the low-temperature water-gas-shift (LT-WGS) reaction was investigated. Catalytic activity was linearly correlated with both surface area of metallic copper (Cu-0) and surface Cu content in the identical copper-metal oxide system. However, activity per Cu-0 surface area changed depending on the metal oxide added. CO2-TPD profile demonstrated that the amount of strong basic sites on Cu-ZnOx and Cu-AlOx catalysts with high activity LT-WGS reactions was much less than those on Cu-FeOx and Cu-CeOx catalysts with low activity. Activity per Cu-0 surface area increased with increasing amount of weak basic sites on Cu-AlOx and Cu-ZnOx catalysts. From these results, it is suggested that in addition to Cu-0 surface area, basicity of a catalyst is one of the factors controlling the catalytic activity of Cu-based catalysts for LT-WGS reaction. (C) 2012 Published by Elsevier B. V.