采用浸渍法制备了质量分数11．32％Cu/γ-Al2 O3催化剂，采用固定床反应器，考察了SO2浓度（0～0．02％）对低浓度甲烷（体积分数，3％）催化燃烧特性的影响，通过反应前后催化剂的微观结构及化学成分检测，结合理论分析，探讨了催化反应的硫中毒原因。研究表明，SO2的通入导致了Cu/γ-Al2 O3催化剂活性及稳定性的降低，在同一反应温度下，甲烷转化率随着SO2浓度的增加而下降。 SEM、EDS、FT-IR、XRD表征结果表明，SO2会导致Cu/γ-Al2 O3催化剂表面出现结块现象，催化剂表面有硫元素的累积，且以硫酸盐的形式存在，其主要成分为硫酸铜（ CuSO4）。在富氧条件下，S O2分子及氧离子在Cu2＋上吸附所形成的硫酸铜，附着在催化剂表面，形成一层坚硬的外壳，是产生硫中毒现象的根本原因。%The Cuγ/-Al2 O3 catalysts with 11.32% copper contents prepared by the incipient wetness im preng ation were tested in a fixed bed reactor.The effects of SO2 concentration ( 0 ~0.02%) on the combustion characteristic and stability of low concentration methane( 3%) oev r Cu /γ-Al2 O3 catalysts were investigated.By the analysis of microstructure and chemical component of fresh and aged catalysts, the mechanism of sulfur poisoning in the catalytic reaction was discussed by combining with the theoretical analysis. The results show that the addition of SO2 in the feed gases leads to a decrease of activity na d stability of the catalysts.The methane conversoi n decreases rapidly with teh increasni g concentration of SO2 .The results of SEM, EDS, FT-IR and XRD reveal that the presence of SO2 in the feed gases can result in agglomeration and accumulation of sulfur on the surface of Cu/γ-Al2 O3 catalyst .Sulfur is in the form of sulfate, which mainly contains copper sulfate ( CuSO4 ) .Under the condition of oxygen enrichment, the copper sulfate produced by the absorption of SO2 and oxygen ions on Cu2+is attached to the surface of catalysts and forms a hard shell, which is the major reason for the sulfur poisoning.
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