【摘要】 通过焙烧碳酸锰粉末制备了高活性含缺陷氧原子的氧化锰材料(MnOx,x=1.6～2.0),用胶溶法制备了高比表面积的SiO2-Al2O3载体,然后用等体积浸渍法制备了不同MnOx担载量的Pd-MnOx/SiO2-Al2O3系列催化剂.结果表明,催化剂活性随MnOx含量的增加而增加,但无载体的MnOx催化剂易脱落,活性降低.在空速(GHSV)为360000h-1的条件下,MnOx含量为80%的催化剂对O3的完全转化温度(T100)为30℃;在GHSV=660000h-1时,MnOx含量在80%～90%的催化剂活性最高,T100为45～50℃,能满足在汽车运行时空气与汽车水箱瞬时接触温度的要求.在45℃和510000h-1条件下对MnOx担载量为80%的催化剂进行95h寿命测试后,O3的转化率大于90%,说明催化剂具有很强的抗失活能力.更多还原

【Abstract】 A highly active manganese dioxide material with deficient oxygen atoms (MnOx,x=1.6-2.0) was prepared by calcining manganese carbonate,and a SiO2-Al2O3 support with large surface area was prepared by the peptizing method. A series of Pd-MnOx/SiO2-Al2O3 catalysts for ozone (O3) decomposition with different MnOx contents were prepared by incipient wet impregnation and characterized by activity tests,N2 adsorption,and life tests. The results of activity tests indicated that catalytic performance increased with MnOx content,but the MnOx catalyst without the support fell off easily and its catalytic performance decreased. At gas hourly space velocity (GHSV)=360 000 h-1,the complete conversion temperature (T100) on the Pd-MnOx/SiO2-Al2O3 catalyst with 80% MnOx content was 30 ℃. At GHSV=660 000 h-1,the catalysts with 80%-90% MnOx had the best performance with T100=45-50 ℃. Touching temperature between air and the water tank of an automobile was satisfied in this temperature range. At 45 ℃ and GHSV=510 000 h-1,O3 conversion on the catalyst with 80%MnOx still kept better standard (>90%),which indicates that the catalyst had very high capacity to resist deactivation after 95 h of life test.更多还原