High Sensitivity Methane Sensors Based On Mesoporous Catalyst

The catalytic combustion type methane sensors are widely used in monitoring coalmine and industrially producting as a kind of important applied sensor,which has highsensitivity to combustible gas. The metal Pd is widely used in catalytic combustiontype sensors, however, Pd particles tend to congregate in conventional r-Al₂O₃at hightemperature,which will make Pd particles inactivate. The mesoporous materials areused as the support of catalyst due to their high surface area and uniform pore size. Inthis experiment we synthetized some kinds of mesoporous materials, and they areused as the support of catalyst in order to improve the perfortances of catalyticcombustion type methane sensors.The mesoporous material Al-TUD-1was synthetized in the first part of theexperiment, and we analysed the material by the method of X-ray diffraction andnitrogen adsorption-desorption, which illustrates that Al-TUD-1has mesoporousstucture.After that,sensing material Pd/Al-TUD-1was synthetized by immersionmethod and homegeneous deposition-precipitaton method, and we tessted the sensorsbased on Pd/Al-TUD-1,the result shows that the sensors loading Pd by homegeneousdeposition-precipitaton method have higher sensitivity than the sensors loading Pd byimmersion method.SBA-15was synthetized in the second part. After that we analysed the materialby X-ray diffraction and nitrogen adsorption-desorption. The result shows thatSBA-15is a kind of mesoporous material, and it has high surface area and uniformpore size.The sensing materials were synthetized by different amounts of Pd, and thesensors based on these sensing material were tested. Compared with conventionalPd/r-Al₂O₃sensors,the sensors based on Pd/SBA-15has higher sensitivity.At last, we synthetized the mesoporous material HMS, and the material wasanalysed by X-ray diffraction and nitrogen adsorption-desorption, which show HMSwas mesoporous material with high surface. What’s more, the metal Pd was loaded onHMS by homegeneous deposition-precipitaton method, and we tested the sensors based on sensing material Pd/HMS. Compared with conventional Pd/r-Al2O3sensors,the result illustrates that HMS has the highest sensitivity, and the sensors based onmesoporous material has more rapid response and recovery rate.