Doping effect of metal oxide on sensing performance of Pd/Al2O3-based methane sensor

Pure and doped γ-Al2O3 by metal oxides including SnO2, ZrO2, CeO2 and MgO were used as the supports of the combustion catalysts. The Al2O3 based supports doped with the metal oxides were prepared by coprecipitation method. The noble metal Pd with 15 wt% loading amount was then loaded on the as-prepared supports using isometric impregnation. The measuring results of Brunauer-Emmett-Teller-specific surface areas revealed that the specific surface areas of supports have been improved to a certain extent by doping of metal oxides. The measurement of gas sensing properties showed that the metal oxides have great influences on the sensitivity to CH4. The sensing performance of catalytic combustion methane sensors had been improved by doping SnO2, ZrO2, CeO2 or MgO in Al2O3.