Microemulsion synthesis of MgO-supported LaMnO3 for catalytic combustion of methane

Catalysts with 20% LaMnO3 supported on MgO have been prepared via CTAB-1-butanol-iso-octane-nitrate salt microemulsion. The preparation method was successfully varied in order to obtain different degrees of interaction between LaMnO3 and MgO as shown by TPR and activity tests after calcination at 900 °C. Activity was tested on structured catalysts with 1.5% CH4 in air as test gas giving a GHSV of 100,000 h−1. The activity was greatly enhanced by supporting LaMnO3 on MgO compared with the bulk LaMnO3. After calcination at 1100 °C both the surface area and TPR profiles were similar, indicating that the preparation method is of little importance at this high temperature due to interaction between the phases. Pure LaMnO3 and MgO were prepared using the same microemulsion method for comparison purposes. Pure MgO showed an impressive thermal stability with a BET surface area exceeding 30 m2/g after calcination at 1300 °C. The method used to prepare pure LaMnO3 appeared not to be suitable since the surface area dropped to 1.1 m2/g already after calcination in 900 °C.