MnO_(x)-CeO_(2) catalysts are developed by hydrolysis driving redox method using acetate precursor(3 Mn1 Ce-Ac) and nitrate precursor(3 Mn1 Ce-N) for the selective catalytic reduction(SCR) of NO_(x) by NH_(3).A counte...MnO_(x)-CeO_(2) catalysts are developed by hydrolysis driving redox method using acetate precursor(3 Mn1 Ce-Ac) and nitrate precursor(3 Mn1 Ce-N) for the selective catalytic reduction(SCR) of NO_(x) by NH_(3).A counterpart sample(Cop-3 Mn1 Ce) was prepared by the NH_(3)·H_(2) O co-precipitation method for comparison purpose.Combining the results of physicochemical properties characterization and performance test,we find that the 3 Mn1 Ce-Ac catalyst with some nanorod structures is highly active for the deNOx process.The SCR activity of the 3 Mn1 Ce-Ac catalyst is more admirable than the 3 Mn1 Ce-N and the Cop-3 Mn1 Ce catalysts due to plentiful Lewis acid sites,excellent low-temperature reducibility,and superior surface area resulted from O_(2) generation during the pre paration procedure.The 3 Mn1 Ce-Ac still exhibits the greatest performance for the deNO_(x )process when gaseous acetone is in the SCR feed gas.The NOx conversion and N2 selectivity over the 3 Mn1 Ce-Ac are both improved by gaseous acetone above150℃ due to the inhibition of SCR undesired side reactions(NSCR & C-O reactions) and "slow-SCR" process.展开更多
Formaldehyde is an important air pollutant and its removal is essential to protect human health and meet environmental regulations.Ag-based catalyst has a considerable potential for HCHO oxidation in low temperature r...Formaldehyde is an important air pollutant and its removal is essential to protect human health and meet environmental regulations.Ag-based catalyst has a considerable potential for HCHO oxidation in low temperature range.The valence state of Ag is one of the key roles in formaldehyde catalytic oxidation.However,its effect on activity is still ambiguous.Non-thermal plasma and conventional calcination were employed to regulate Ag valence state in this study.Three Ag-Co/CeO_(2)catalysts with totally different distribution of Ag species were obtained.A special mixed Ag valence state,~50%Ag^(δ+)with a few Ag^(0)and Ag^(+),was achieved by plasma activation.It had the merits of both good activity and stability.A close relationship between Ag valence state and the activity for HCHO oxidation was established.The activity of different Ag species follows the order:Ag^(δ+)+Ag^(0)+Ag^(+)>Ag^(δ+)>Ag^(0)>Ag^(+).展开更多
基金supported by the Key Laboratory of Water and Air Pollution Control of Guangdong province,China (No.2017A030314001)the National Key Research and Development Plan (No.2019YFC0214303)+1 种基金Central Public-Interest Scientific Institution Basal Research Fund (No.PM-zx703-202002-015)the National Natural Science Foundation of China (No.22076224)。
文摘MnO_(x)-CeO_(2) catalysts are developed by hydrolysis driving redox method using acetate precursor(3 Mn1 Ce-Ac) and nitrate precursor(3 Mn1 Ce-N) for the selective catalytic reduction(SCR) of NO_(x) by NH_(3).A counterpart sample(Cop-3 Mn1 Ce) was prepared by the NH_(3)·H_(2) O co-precipitation method for comparison purpose.Combining the results of physicochemical properties characterization and performance test,we find that the 3 Mn1 Ce-Ac catalyst with some nanorod structures is highly active for the deNOx process.The SCR activity of the 3 Mn1 Ce-Ac catalyst is more admirable than the 3 Mn1 Ce-N and the Cop-3 Mn1 Ce catalysts due to plentiful Lewis acid sites,excellent low-temperature reducibility,and superior surface area resulted from O_(2) generation during the pre paration procedure.The 3 Mn1 Ce-Ac still exhibits the greatest performance for the deNO_(x )process when gaseous acetone is in the SCR feed gas.The NOx conversion and N2 selectivity over the 3 Mn1 Ce-Ac are both improved by gaseous acetone above150℃ due to the inhibition of SCR undesired side reactions(NSCR & C-O reactions) and "slow-SCR" process.
基金supported by the National Natural Science Foundation of China(NSFC,Nos.22006166 and 22076224)the China Postdoctoral Science Foundation(No.2019M653184)+1 种基金Guangdong Basic and Applied Basic Research Foundation(No.2020A1515010865)Fundamental Research Funds for the Central Universities(Nos.20lgjc03 and 20lgpy95)。
文摘Formaldehyde is an important air pollutant and its removal is essential to protect human health and meet environmental regulations.Ag-based catalyst has a considerable potential for HCHO oxidation in low temperature range.The valence state of Ag is one of the key roles in formaldehyde catalytic oxidation.However,its effect on activity is still ambiguous.Non-thermal plasma and conventional calcination were employed to regulate Ag valence state in this study.Three Ag-Co/CeO_(2)catalysts with totally different distribution of Ag species were obtained.A special mixed Ag valence state,~50%Ag^(δ+)with a few Ag^(0)and Ag^(+),was achieved by plasma activation.It had the merits of both good activity and stability.A close relationship between Ag valence state and the activity for HCHO oxidation was established.The activity of different Ag species follows the order:Ag^(δ+)+Ag^(0)+Ag^(+)>Ag^(δ+)>Ag^(0)>Ag^(+).
