Effect of the flowing gases of steam and CO2 on the texture and catalytic activity for methane combustion of MgO powders

In this work, the MgO powders was prepared by the precipitation method with carbonate following calcination at 1200 °C, and then the obtained MgO powders was treated under the flowing gaseous mixture of steam and CO2. The variations of textural properties and activity for methane combustion of the MgO sample were investigated. The sample was characterized by N2 adsorption isotherm, TEM, XRD, and TG-DTA. The results showed that the treatment temperature and the CO concentration have a significant influence on the textural properties of the MgO sample. After run at 700 °C for 24 h under the flowing gaseous mixture of steam/CO2/N2 (CO2/N2 = 15/85 volume ratio), the maximum pore sizes varied and the pore volumes increased obviously; and remarkably, the surface area of the MgO sample increased from 37.9 to 80.1 m2 g−1. It was proposed that during the process, the disaggregation and rearrangement of the particles have occurred, leading to the obvious variations of the textural properties of the sample. As a result, the treated MgO sample showed a higher activity for methane combustion than the original one.