中文摘要：

分别采用浸渍法和机械混合法制备了Cr改性的In/WO3/ZrO2（In/WZr）催化剂,考察了改性前后催化剂的CH4选择性催化还原NO的活性.结果表明,将Cr2O3与In/WZr机械混合可显著提高In/WZr催化剂活性,Cr的加入促进了气相中NO向NO2的转化.而浸渍法制备的Cr/In/WZr催化剂活性远低于改性前的In/WZr催化剂,这是由于在制备过程中部分Cr2O3转化为CrO3,使其氧化性大大提高,从而将CH4完全氧化为CO2和H2O,不利于将CH4活化为反应所需的中间活性物种.

英文摘要：

Cr-modified In/WO3/ZrO2 （In/WZr） catalysts were prepared by impregnation and mechanical mixing methods. Their activity for selective catalytic reduction of NO with CH4 was investigated. The results showed that the catalyst activity was enhanced by mixing Cr2O3 with In/WZr. The enhancement of the activity was due to the oxidation ability of Cr2O3, which improved the conversion of NO to NO2. However, for the catalysts prepared by impregnation, some of the trivalent chromium （Cr^3＋） was converted to Cr^6＋, which resulted in the lower activity than the initial In/WZr catalyst by the complete oxidation of CH4 to CO2 and H2O.