Probing the thermal-enhanced catalytic activity of CO oxidation over Pd/OMS-2 catalysts

Abstract

The present research has probed the effect of different thermal-treatment temperatures on the catalytic activity of CO oxidation and the physio-chemical properties of an OMS-2 supported palladium catalyst. The catalytic activity of Pd/OMS-2 increased with an increase in the thermal-treatment temperature from 300 to 500 °C. The optimal Pd/OMS-2 catalyst exhibited over 99% CO conversion at 35 °C. An elevated thermal-treatment temperature up to 500 °C led to a decrease in OMS-2 crystallinity and surface chemisorbed oxygen (–OH), while the surface atomic ratios of oxygen/Mn and palladium increased with the calcination temperature. A high thermal-treatment temperature above 500 °C led to the phase transformation of OMS-2 into Mn₂O₃, and an abrupt alteration in the Pd–support interaction and deactivation of the Pd/OMS-2 catalyst.