Au/SnO_2催化氧化CO性能的研究

Study on the catalytic performance of Au/SnO_2 for CO oxidation

以SnO2为载体,Au为活性组分,采用真空浸渍法、共沉淀法、沉积-沉淀法制备CO氧化的催化剂,同时还制备双金属体系催化剂Au-Pd/SnO2和Au-Pt/SnO2。用气相色谱对所制备的催化剂进行活性评价,运用DSC、SEM、XRD、BET等对催化剂进行表征。在本实验条件下,载体二氧化锡焙烧温度为500℃,催化剂成型温度为350℃,金负载量为3%(wt.)时,用沉积-沉淀法制备的Au/SnO2活性最好,在18℃,空速为24 000 h-1条件下就能将CO(浓度为4%)完全氧化为CO2;添加铂和钯可提高Au/SnO2对CO的催化活性。

Serials of Au/SnO2 catalysts for CO oxidation were prepared by different methods including incipient-vacuum, corecipitation and deposition-precipitation and the preparation conditions of catalysts were optimized. Au-Pd/SnO2 and Au-Pt/SnO2 catalysts were also prepared by co-precipitation method. The activities of all prepared catalysts to carbon monoxide oxidation were tested by the means of GC. The catalysts were characterized by DSC, SEM, XRD and BET. The factors effecting on catalytic activity were discussed. From this study, it could be concluded that when SnO2 calcination temperature was 500℃ , catalysts calcination temperature was 350℃ , gold loading was 3% （wt.）, Au/SnO2 catalysts prepared by deposition-precipitation method had the best activity, which made CO conversion be 100% at reaction temperature of 18℃ . Adding Pd or Pt into the catalysts Au/SnO2, which prepared by co-precipitation method, can improve the catalytic activity to CO oxidation.