Influence of group IIA metals on the performance of the Ni[sbnd]Cu/CeO2[sbnd]Al2O3 catalysts in high-temperature water gas shift reaction

Abstract

In this research, the effect of alkaline earth promoters (Mg, Sr, Ca and Ba) on the catalytic performance of the 7 wt%Ni-7.5 wt%Cu/CeO2Al2O3 catalyst in high-temperature water gas shift (HTWS) reaction was studied. The mesoporous support was prepared via a simple solid-state method with the BET surface area of 94.46 m2 g−1. The results indicated that among the prepared catalysts, the Ba-promoted catalyst demonstrated a high CO conversion (68.9% at 450 °C) and a low decline in BET area after the reaction. The maximum methane production for this catalyst was lower than that observed for the unpromoted catalyst that could be related to the higher concentration of basic sites in the Ba-promoted catalyst. Although, a higher amount of Ba can improve the selectivity toward water gas shift reaction, increasing the Ba content from 4 wt% to 6 wt% had a negative effect on the activity. Moreover, the addition of Ba to 7Ni-7.5Cu/CeO2Al2O3 improved the long-time stability of the catalyst.