The inhibiting effect of SO₂ on the catalytic activity of the monometallic Pt/Al₂O₃ and Pd/Al₂O₃, as well as on bimetallic PtPd/Al₂O₃ catalyst for the complete oxidation of methane under lean conditions has been studied. Flow reactor experiments, in-situ DRIFT spectroscopy and characterization with XPS, STEM-EDX were performed. It was found that the addition of Pt to the Pd/Al₂O₃ resulted in a catalyst that was more robust towards sulfur poisoning. XPS results revealed residual sulfates on catalyst surface after regeneration. This was confirmed with EDX analysis, which demonstrated that sulfur was accumulated in noble metal particles and especially in the region of the particle rich in Pt. Although the catalyst has been deactivated in the presence of both SO₂ and H₂O, an additional presence of NO in the gas mixture of reactants resulted in an increased lifetime of the sample under reaction conditions. This NO effect strongly depends on the temperature of experiments and is most intense at a temperature close to 550 °C A postponed inhibition caused by the addition of NO may be explained by the DRIFTS results, which demonstrated that the presence of NO lowers the sulfate formation and mostly surface sulfites are observed that increase the lifetime of the catalyst during SO₂ exposure.

SO ₂对贫金属条件下甲烷完全氧化的单金属Pt / Al ₂ O ₃和Pd / Al ₂ O ₃以及双金属PtPd / Al ₂ O ₃催化剂的催化活性的抑制作用一直是研究过。进行了流动反应器实验，原位DRIFT光谱以及XPS，STEM-EDX的表征。发现在Pd / Al ₂ O _3中添加了Pt导致产生的催化剂对硫中毒更有效。XPS结果表明再生后催化剂表面残留有硫酸盐。用EDX分析证实了这一点，EDX分析表明硫在贵金属颗粒中，特别是在富含Pt的颗粒区域中积累。尽管催化剂在SO ₂和H ₂的存在下均已失活○，在反应物的气体混合物中还存在NO，导致样品在反应条件下的寿命增加。这种NO效应在很大程度上取决于实验温度，并且在接近550°CA的温度下最强烈，这可能是由DRIFTS结果解释的，这是由于添加NO引起的延迟抑制作用，该结果表明NO的存在会降低硫酸盐的生成并降低NO的含量。观察到大部分表面亚硫酸盐会延长暴露于SO ₂期间催化剂的寿命。