Effect of structural and acidity/basicity changes of CuO–CeO2 catalysts on their activity for water–gas shift reaction

The objective of this work was to investigate the influence of CuO loading and catalyst pretreatment procedure to derive an optimal CuO–CeO2 catalyst for the water–gas shift reaction (WGS), and to study in detail structure– and surface acidity–activity relationships. Catalyst samples prepared by coprecipitation and a 10, 15 and 20 mol% CuO content were examined by XRD, BET and TPR/TPD analyses and subjected to pulse WGS activity tests in the temperature range of 180–400 °C. Strong structure–activity dependence in the WGS reaction was observed for all catalyst samples. It was established that increasing CuO content has a positive effect on H2 production during the WGS reaction, due to favored CeO2 reduction. Increasing calcination temperature on the other hand reduces the BET surface area, induced by CuO sintering and agglomeration of CeO2 particles, resulting in a negative effect on H2 production. Distinctive WGS activity dependence on surface acidity was observed and investigated.