TAP studies on 2% Ag/γ–Al2O3catalyst for selective reduction of oxygen in a H2-rich ethylene feed

Abstract

Catalysts currently employed for the polymerization of ethylene have previously been found to deactivate in the presence of oxygen. It is, therefore, important that oxygen is removed from the ethylene feedstock prior to the polymerization. The Ag/γ–Al₂O₃ catalyst exhibits excellent activity and selectivity toward oxygen reduction with hydrogen in the presence of ethylene. TAP vacuum pulse experiments have been utilised to understand the catalytic behaviour of the Ag/γ–Al₂O₃ catalyst. TAP multi-pulse experiments have determined the types of active sites that are found on the Ag/γ–Al₂O₃ catalyst, and the intrinsic activity of these sites. The lifetime of the reactive adsorbed oxygen intermediate has also been determined through TAP consecutive pulse experiments. Multi-pulse and consecutive pulse data have been combined with ethylene adsorption/desorption rate constants to provide an overview of the Ag/γ–Al₂O₃ catalyst system.