NH_(3)-SCR performances were explored to the relationship between structure morphology and physio-chemical properties over low-dimensional ternary Mn-based catalysts prepared by one-step synthesis method.Due to its st...NH_(3)-SCR performances were explored to the relationship between structure morphology and physio-chemical properties over low-dimensional ternary Mn-based catalysts prepared by one-step synthesis method.Due to its strong oxidation performance,Sn-MnO_(x) was prone to side reactions between NO,NH_(3)and O_(2),resulting in the generation of more NO_(2)and N_(2)O,here most of N_(2)O was driven from the non-selective oxidation of NH_(3),while a small part generated from the side reaction between NH_(3)and NO_(2).Co or Ni doping into Sn-MnO_(x) as solid solution components obviously stronged the electronic interaction for actively mobilization and weakened the oxidation performance for signally reducing the selective tendency of side reactions to N_(2)O.The optimal modification resulted in improving the surface area and enhancing the strong interaction between polyvalent cations in Co/Ni-Mn-SnO_(2)to provide more surface adsorbed oxygen,active sites of Mn^(3+) and Mn^(4+),high-content Sn^(4+) and plentiful Lewis-acidity for more active intermediates,which significantly broadened the activity window of Sn-MnOx,improved the N^(2) selectivity by inhibiting N_(2)O formation,and also contributed to an acceptable resistances to water and sulfur.At low reaction temperatures,the SCR reactions over three catalysts mainly obeyed the typical Elye-rideal(E-R)routs via the reactions of adsorbed L-NH_(x)(x=3,2,1)and B-NH_(4)^(+) with the gaseous NO to generate N_(2) but also N_(2)O by-products.Except for the above basic E-R reactions,as increasing the reaction temperature,the main adsorbed NO_(x)-species were bidentate nitrates that were also active in the Langmuir-Hinshelwood reactions with adsorbed L-NH_(x) species over Co/Ni modified Mn-SnO_(2) catalyst.展开更多
基金financially supported by National Natural Science Foundation of China (Nos. U20A20130, 21806009)China Postdoctoral Science Foundation (2019T120049)Fundamental Research Funds for the Central Universities (No. 06500152).
文摘NH_(3)-SCR performances were explored to the relationship between structure morphology and physio-chemical properties over low-dimensional ternary Mn-based catalysts prepared by one-step synthesis method.Due to its strong oxidation performance,Sn-MnO_(x) was prone to side reactions between NO,NH_(3)and O_(2),resulting in the generation of more NO_(2)and N_(2)O,here most of N_(2)O was driven from the non-selective oxidation of NH_(3),while a small part generated from the side reaction between NH_(3)and NO_(2).Co or Ni doping into Sn-MnO_(x) as solid solution components obviously stronged the electronic interaction for actively mobilization and weakened the oxidation performance for signally reducing the selective tendency of side reactions to N_(2)O.The optimal modification resulted in improving the surface area and enhancing the strong interaction between polyvalent cations in Co/Ni-Mn-SnO_(2)to provide more surface adsorbed oxygen,active sites of Mn^(3+) and Mn^(4+),high-content Sn^(4+) and plentiful Lewis-acidity for more active intermediates,which significantly broadened the activity window of Sn-MnOx,improved the N^(2) selectivity by inhibiting N_(2)O formation,and also contributed to an acceptable resistances to water and sulfur.At low reaction temperatures,the SCR reactions over three catalysts mainly obeyed the typical Elye-rideal(E-R)routs via the reactions of adsorbed L-NH_(x)(x=3,2,1)and B-NH_(4)^(+) with the gaseous NO to generate N_(2) but also N_(2)O by-products.Except for the above basic E-R reactions,as increasing the reaction temperature,the main adsorbed NO_(x)-species were bidentate nitrates that were also active in the Langmuir-Hinshelwood reactions with adsorbed L-NH_(x) species over Co/Ni modified Mn-SnO_(2) catalyst.
