The successful control of hydrocarbon and CO emissions from low-temperature diesel exhausts requires the use of highly active co-oxidation catalysts.In this study,Sn was used to enhance the catalytic performance of Pd...The successful control of hydrocarbon and CO emissions from low-temperature diesel exhausts requires the use of highly active co-oxidation catalysts.In this study,Sn was used to enhance the catalytic performance of Pd/CeO_(2)in CO and C_(3)H_(6)co-oxidation conditions.CeO_(2)with added stannum(Sn)was prepared as a support using the co-precipitation method,and Pd was loaded onto the support using the impregnation method.After Sn addition(the optimal Ce/Sn ratio is 0.75:0.25),the T_(50)values of CO and C_(3)H_(6)are reduced by 20 and 32℃,respectively.A series of characterization methods indicates that the addition of Sn to the support greatly enhances its lattice oxygen mobility and increases the proportion of PdO.During the co-oxidation process,stronger lattice oxygen mobility allows CO to react faster through the Mars-van Krevelen mechanism,weakening the competition with C_(3)H_(6)for O_(2).A higher PdO content enhances the C_(3)H_(6)oxidation capability.Moreover,CO can more readily reduce PdO than Pd^(2+)in solid solution with the support,which consequently further enhances co-oxidation activity.Therefore,the addition of Sn is a simple and effective strategy for enhancing the performance of Pd/CeO_(2)catalysts in CO and C_(3)H_(6)co-oxidation reactions.Furthermore,the promotional effect of CO achieved in this study contributes to a deeper understanding of the interactions that occur during the co-oxidation of C_(3)H_(6)and CO.展开更多
基金Project supported by the National Key R&D Program of China(2022YFC3701804)the National Natural Science Foundation of China(52225004)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA23010201)the Youth Innovation Promotion Association of Chinese Academy of Sciences(2022309)。
文摘The successful control of hydrocarbon and CO emissions from low-temperature diesel exhausts requires the use of highly active co-oxidation catalysts.In this study,Sn was used to enhance the catalytic performance of Pd/CeO_(2)in CO and C_(3)H_(6)co-oxidation conditions.CeO_(2)with added stannum(Sn)was prepared as a support using the co-precipitation method,and Pd was loaded onto the support using the impregnation method.After Sn addition(the optimal Ce/Sn ratio is 0.75:0.25),the T_(50)values of CO and C_(3)H_(6)are reduced by 20 and 32℃,respectively.A series of characterization methods indicates that the addition of Sn to the support greatly enhances its lattice oxygen mobility and increases the proportion of PdO.During the co-oxidation process,stronger lattice oxygen mobility allows CO to react faster through the Mars-van Krevelen mechanism,weakening the competition with C_(3)H_(6)for O_(2).A higher PdO content enhances the C_(3)H_(6)oxidation capability.Moreover,CO can more readily reduce PdO than Pd^(2+)in solid solution with the support,which consequently further enhances co-oxidation activity.Therefore,the addition of Sn is a simple and effective strategy for enhancing the performance of Pd/CeO_(2)catalysts in CO and C_(3)H_(6)co-oxidation reactions.Furthermore,the promotional effect of CO achieved in this study contributes to a deeper understanding of the interactions that occur during the co-oxidation of C_(3)H_(6)and CO.
