Effects of precipitants on the catalytic performance of Cu/CeO2 catalysts for the water-gas shift reaction

The water-gas shift (WGS) reaction has been attracting interest for on-site small-scale production of hydrogen. This study discusses the fabrication of inexpensive, high-performance Cu/CeO2 catalysts. To synthesize these catalysts, CeO2 supports were prepared using K2CO3/KOH as precipitants in different ratios. First, 20 wt% Cu was loaded onto the prepared CeO2 supports through incipient wetness impregnation. The ratios of the precipitants affect the physicochemical properties of the Cu/CeO2 catalysts, which in turn affects the catalytic performance. On increasing the K2CO3/KOH ratio, the surface area, oxygen storage capacity, and reducibility increased, while Cu dispersion decreased. To achieve high activity of Cu/CeO2 catalysts, the CeO2 support should be synthesized at the K2CO3 : KOH ratio of 3 : 1. This Cu/CeO2 catalyst exhibits the highest CO conversion between 200 and 400 degrees C, even at a very high gas hourly specific velocity of 50 102 h(-1). This result shows that the catalytic performance is greatly influenced by various physicochemical properties such as surface area, oxygen storage capacity, Cu dispersion, and reducibility.