氧化锡基甲烷催化燃烧催化剂的硫中毒反应机理

测定了几种活性较高的氧化锡基甲烷燃烧催化剂在200×10－6（φ）SO2存在下的催化活性.结果发现,SnCrO样品具有很好的抗硫性能,而SnCuO及SnCoO样品在SO2存在时的活性大大降低.用XRD、BET、XPS、FT-IR及DTA-TG等技术对反应前后的样品进行了表征,结果表明,硫酸盐的热稳定性对催化剂在SO2处理过程中的变化起决定作用.在实验的温度下（500 ℃）,Co2(SO4)3和CuSO4均能稳定存在,而Cr2(SO4)3会分解.SnCrO样品在SO2存在下反应时只是表面吸附少量硫酸根,因此其催化活性基本保持不变.这是SnCrO样品具有良好抗硫性能的原因.

Sulphur Poisoning Mechanism of SnO2 Based Catalysts for Methane Combustion

The catalytic activity of several SnO2 based catalysts for methane combustion in the presence of 200×10－6（φ,volume fraction） SO2 were tested. The results showed that among these samples studied SnCrO possessed the highest resistance to sulphur poisoning, while the catalytic activity of SnCuO and SnCoO samples decreased significantly. XRD, BET, XPS, FT-IR and DTA-TG techniques were employed to characterize the samples before and after reaction in SO2, and it was found that the thermal stability of the respective metal sulfates played an important role in the combustions of methane in the presence of SO2. At 500 ℃,Co2(SO4)3 and CuSO4 are stable but Cr2(SO4)3 can decompose, therefore, during the reaction in 200×10－6（φ） SO2, SnCrO sample only adsorbs a small amount of SO42- ions on its surface and the activity remains almost unchanged, which is the reason for the highest resistance of SnCrO sample to sulphur poisoning.