Preferential oxidation of carbon monoxide on Pt/γ-Al2O3 catalyst: Effect of adding ceria and nickel

Abstract

The effect of adding ceria and nickel to Pt/γ-Al2O3 catalyst was studied for preferential oxidation (PROX) of CO. The catalysts were characterized by XRD, BET, TPR, XRF and H2 chemisorption techniques. An optimum amount of ceria and nickel was required for improving the activity and selectivity. Adding small amount of ceria (1 wt. %) and/or nickel (1 wt. %) improved the activity and selectivity of 1% Pt/γ-Al2O3 catalyst. When 1 wt. % of both the promoters i.e. ceria and nickel were added to 1% Pt/γ-Al2O3 catalyst, a significant improvement was observed in its activity and selectivity. With 1%Pt-1%Ni/1%CeO2/γ-Al2O3 catalyst, complete CO conversion was obtained even at 100 °C for a feed containing 1% CO, 1% O2, 40% H2 and balance N2. This novel catalyst also widened the temperature range of operation for complete CO conversion from 100 to 200 °C and no methanation activity was observed in this temperature range. The high activity and selectivity of this catalyst was most likely due to the formation of bimetallic Pt–Ni phase on the catalyst and higher dispersion of Pt metal on the catalyst as observed from H2 chemisorption.