In order to prevent the emission of NO_(x) from diesel engines during the cold-start period,a NO_(x) adsorption selective catalytic reduction(AdSCR)catalyst was prepared by combining a selective catalytic reduction(SC...In order to prevent the emission of NO_(x) from diesel engines during the cold-start period,a NO_(x) adsorption selective catalytic reduction(AdSCR)catalyst was prepared by combining a selective catalytic reduction(SCR)catalyst with an NO_(x) adsorbent.In this study,CeO_(2)/Al_(2)O_(3)(Ce/Al)was employed as the NO_(x) adsorbent,combined with WO_(3)/CeZrO_(x)(W/CZ)as a promising SCR catalyst,to prepare an AdSCR catalyst.The characterization results demonstrate that the synergistic effects of the combined catalyst significantly enhance the activated oxidation of NO_(x) in comparison to the individual catalysts.The addition of Ce/Al enhances the adsorption of NO_(x) on the catalysts,which is then reduced to N_(2) and H_(2)O by NH_(3) under the action of W/CZ catalysts.The results of the NH_(3)-SCR activity test indicate that an excess of Ce/Al results in a reduction in SCR performance,suggesting that there is a balance between the SCR component and the NO_(x) adsorbent.The optimal combination of 20 wt%Ce/Al+W/CZ(20CA-W/CZ)catalyst demonstrates enhanced NO_(x) adsorption-storage performance while maintaining the exceptional NH_(3)-SCR performance.The NO_(x) complete storage time of the 20CA-W/CZ catalyst is 125 s,which is nearly twice as long as that of the Ce/Al and W/CZ catalysts.Furthermore,the NO_(x) conversion of the 20CA-W/CZ catalyst at low temperatures is approximately 10%higher than that of the W/CZ catalyst.The findings of this study offer a promising s trategy for the design of high-performance AdSCR catalysts in the future.展开更多
基金Project supported by the National Natural Science Foundation of China(22072098)the Sichuan Science and Technology Program(2022ZHCG0125)。
文摘In order to prevent the emission of NO_(x) from diesel engines during the cold-start period,a NO_(x) adsorption selective catalytic reduction(AdSCR)catalyst was prepared by combining a selective catalytic reduction(SCR)catalyst with an NO_(x) adsorbent.In this study,CeO_(2)/Al_(2)O_(3)(Ce/Al)was employed as the NO_(x) adsorbent,combined with WO_(3)/CeZrO_(x)(W/CZ)as a promising SCR catalyst,to prepare an AdSCR catalyst.The characterization results demonstrate that the synergistic effects of the combined catalyst significantly enhance the activated oxidation of NO_(x) in comparison to the individual catalysts.The addition of Ce/Al enhances the adsorption of NO_(x) on the catalysts,which is then reduced to N_(2) and H_(2)O by NH_(3) under the action of W/CZ catalysts.The results of the NH_(3)-SCR activity test indicate that an excess of Ce/Al results in a reduction in SCR performance,suggesting that there is a balance between the SCR component and the NO_(x) adsorbent.The optimal combination of 20 wt%Ce/Al+W/CZ(20CA-W/CZ)catalyst demonstrates enhanced NO_(x) adsorption-storage performance while maintaining the exceptional NH_(3)-SCR performance.The NO_(x) complete storage time of the 20CA-W/CZ catalyst is 125 s,which is nearly twice as long as that of the Ce/Al and W/CZ catalysts.Furthermore,the NO_(x) conversion of the 20CA-W/CZ catalyst at low temperatures is approximately 10%higher than that of the W/CZ catalyst.The findings of this study offer a promising s trategy for the design of high-performance AdSCR catalysts in the future.
