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采用共沉淀法制备了不同SnO2 含量的SnO2 TiO2 固溶体催化剂 .发现该催化剂对以CO为还原剂同时还原SO2 和NO生成S和N2 的反应具有高活性和高稳定性 .SnO2 含量为 5 0 % (摩尔分数 )的样品活性最高 ,在 35 0℃ ,0 0 5 2 5 %SO2 ,0 0 5 2 %NO ,0 2 0 8%CO和空速 30 0 0h 1的条件下 ,NO转化率接近 10 0 % ,SO2 转化率为 88% ,S和N2 的选择性都接近10 0 % ,反应过程中没有剧毒气体COS生成 .对于SO2 +CO反应 ,该样品也显示了极高的活性 ,在 35 0℃ ,0 10 5 %SO2 ,0 2 0 8%CO和空速 30 0 0h-1的条件下 ,SO2 转化率达 98% ,S的选择性近 10 0 % .但该催化剂对NO +CO反应的催化活性不高 ,在 35 0℃ ,0 10 2 5 %NO ,0 2 0 8%CO ,空速 30 0 0h-1的条件下 ,NO的转化率仅为 5 0 % .上述结果表明 ,SO2 对NO +CO反应具有促进作用 .单独的SnO2 或TiO2 对SO2 +CO ,NO +CO或SO2 +NO +CO反应的催化活性都很低 ,但SnO2 和TiO2 形成SnO2 TiO2 固溶体后催化活性显著增大 ,说明SnO2 和TiO2 之间产生了协同效应
SnO2 TiO2 solid solution catalysts with different content of SnO2 were prepared by coprecipitation method.The catalysts were found to have high activity and high stability for the reaction of reducing SO2 and NO simultaneously to form S and N2 by using CO as reductant.The content of SnO2 was 50% The molar ratio of NO to NO (superscript 3 subscript 2)) was the highest. Under the conditions of 35 0 ℃, 0 0 5 2 5% SO 2, 0 0 5 2% NO, 0 0 0 0 0% CO and space velocity 30 0 0 h 1, 0%, the conversion of SO2 is 88%, the selectivity of S and N2 are close to 100%, and no toxic gas COS is formed during the reaction.For the SO2 + CO reaction, the sample also shows a very high activity in 35 The conversion of SO2 was 98% and the selectivity of S was nearly 100% under the conditions of 0 ℃, 0 105% SO2, 0 208% CO and space velocity 30 000h-1. However, The catalytic activity of the reaction is not high, and the conversion of NO is only 50% at 350 ℃, 0 10 2 5% NO, 0 208% CO and space velocity 30 000h-1. , And SO2 promoted the reaction of NO + CO. The catalytic activity of SnO2 or TiO2 alone for the reaction of SO2 + CO, NO + CO or SO2 + NO + CO was low, but the catalytic activity of SnO2 and TiO2 for the formation of SnO2 TiO2 solid solution was significantly Increasing, indicating a synergistic effect between SnO2 and TiO2