Promotion of a Pd/Al2O3 close-coupled catalyst by Ni

The influence of a nickel promoter on the catalytic behavior of a modified alumina supported Pd close-coupled catalyst was investigated. Doping with nickel improved the catalytic activity for the reactions of C3H8, especially over the aged catalyst. T50 and T90 of the aged Pd catalyst were decreased by 31 and 30 °C, respectively. The single reaction results revealed that doping with Ni promoted the catalytic activity for the C3H8 + NO reaction. The fresh and aged catalysts were characterized by H2-temperature-programmed reduction, CO chemisorption, high resolution transmission electron microscopy, and X-ray photoelectron spectroscopy, which revealed that the doping with Ni inhibited the sintering of active PdOx species and the formation of undesired metallic Pd0, and led to improved reducibility of active PdOx and increased the surface area of PdOx species.

Graphical AbstractAddition of Ni to a Pd/Al2O3 close-coupled catalyst improved the catalytic activity for C3H8 conversion and increased the amount of active PdOx species. The figure describes how C3H8 conversion over the aged Pd/Al2O3 and PdNi/Al2O3 close-coupled catalysts occurs.Figure optionsDownload as PowerPoint slide