Lean methane catalytic combustion over the mesoporous MnOx-Ni/MgAl2O4 catalysts: Effects of Mn loading

Abstract

In the current investigation, the textural features and catalytic efficiency of the Mn-promoted Ni/MgAl2O4 catalysts were evaluated in the catalytic combustion of lean methane. The results demonstrated that adding manganese oxide up to 5 wt.% to the catalyst improved the structural features and light-off temperatures due to the increase of the reduction degree and oxygen vacancies. The role of the Tcalcination and processing factors on the methane conversion of the 5%Mn-20%Ni/MgAl2O4 catalyst was also studied. The results indicated that the CH4 conversion decreased with the increment of O2/CH4 molar ratio and GHSV value. The stability test revealed that the prepared sample exhibited high stability during 10 h time on stream. Furthermore, the obtained results indicated that the BET area, reduction degree, oxygen mobility, and catalytic performance increased with decreasing the calcination temperature from 700 to 500 °C.