The nature and distribution of Cu species in Cu-SSZ-13 play a vital role in selective catalytic reduction of NO by NH3(NH3-SCR),but existing methods for adjusting the Cu distribution are complex and difficult to contr...The nature and distribution of Cu species in Cu-SSZ-13 play a vital role in selective catalytic reduction of NO by NH3(NH3-SCR),but existing methods for adjusting the Cu distribution are complex and difficult to control.Herein,we report a simple and effective ion-exchange approach to regulate the Cu distribution in the one-pot synthesized Cu-SSZ-13 that possesses sufficient initial Cu species and thus provides a“natural environment”for adjusting Cu distribution precisely.By using this proposed strategy,a series of Cu-SSZ-13x zeolites with different Cu contents and distributions were obtained.It is shown that the dealumination of the as-synthesized Cu-SSZ-13 during the ion-exchange generates abundant vacant sites in the double six-membered-rings of the SSZ-13 zeolite for relocating Cu2+species and thus allows the redistribution of the Cu species.The catalytic results showed that the ion-exchanged Cu-SSZ-13 zeolites exhibit quite different catalytic performance in NH3-SCR reaction but superior to the parent counterpart.The structure–activity relationship analysis indicates that the redistribution of Cu species rather than other factors(e.g.,crystallinity,chemical composition,and porous structure)is responsible for the improved NH3-SCR performance and SO_(2) and H_(2)O resistance.Our work offers an effective method to precisely adjust the Cu distribution in preparing the industrial SCR catalysts.展开更多
Honeycomb cordierite coated with Cu-SSZ-13 zeolite is widely used for the selective catalytic reduction of NO_(x) with NH_(3)(NH_(3)-SCR)to reduce pollutants from vehicle emissions.However,conventional honeycomb catal...Honeycomb cordierite coated with Cu-SSZ-13 zeolite is widely used for the selective catalytic reduction of NO_(x) with NH_(3)(NH_(3)-SCR)to reduce pollutants from vehicle emissions.However,conventional honeycomb catalysts fabricated via coating techniques are limited by low zeolite loadings,loss of the deposited zeolites,and complicated preparation processes.Herein,a facile,one-step three-dimensional(3D)printing strategy is developed to construct MnO_(x)/Cu-SSZ-13 monolithic catalysts with excellent catalytic performance for NH_(3)-SCR.Iron-containing halloysite nanotubes(Fe-HNTs)are introduced as printing ink additives to ensure mechanical stability and modulate the NH_(3)-SCR performance of monolithic catalysts in high temperature conditions.In situ incorporation of Mn into the Cu-SSZ-13 zeolite monoliths during the 3D printing process boosts the mechanical strength of the monolithic structures from 2.54 MPa to 4.33 MPa as well as broadens the temperature window(165-550℃)of the catalysts for NH_(3)-SCR with NO_(x) conversion of above 80%.Such robust multicomponent-integrated 3D-printed selfsupporting catalysts not only possess high zeolite loading and excellent catalytic activity,but also avoid complicated manufacturing processes,which contrasts with conventional honeycomb catalysts fabricated by extrusion coupled with coating.展开更多
A new type of zeolite composite antibacterial agents was prepared by introducing zinc oxide and copper ions into 13 X zeolite through the coprecipitation and ion-exchange methods. The structural properties of the test...A new type of zeolite composite antibacterial agents was prepared by introducing zinc oxide and copper ions into 13 X zeolite through the coprecipitation and ion-exchange methods. The structural properties of the tested antibacterial material were characterized and the antibacterial activity was evaluated. In Cu^(2+)/ZnO-13 X(CZ-13), zinc oxide and copper ions were either embedded in the interlayer space or dispersed on surface of 13 X zeolite. Excellent antimicrobial activity of CZ-13 was observed on Escherichia coli(E. coli) and Staphylococcus aureus(S.aureus). In the case of Cu^(2+)/ZnO-13 X, both MIC and MBC against E.coli were 0.2 mg/mL and 0.8 mg/mL. For S.aureus, CZ-13 also showed similar antibacterial properties. The bacterial cells turned from normal rod-shape into irregular shapes after treatment with the tested CZ-13. An increase of the intracellular enzyme activity after CZ-13 addition suggested that the permeability of the cell membrane increased and bacteria were damaged.展开更多
Blast furnace gas(BFG)is an important by-product energy for the iron and steel industry and has been widely used for heating or electricity generation.However,the undesirable contaminants in BFG(especially H_(2)S)gene...Blast furnace gas(BFG)is an important by-product energy for the iron and steel industry and has been widely used for heating or electricity generation.However,the undesirable contaminants in BFG(especially H_(2)S)generate harmful environmental emissions.The desulfurization of BFG is urgent for integrated steel plants due to the stringent ultra-low emission standards.Compared with other desulfurization materials,zeolite-based adsorbents represent a viable option with low costs and long service life.In this study,an ammonia-induced CuO modified 13X adsorbent(NH_(3)–CuO/13X)was prepared for H_(2)S removal from simulated BFG at low temperature.The XRD,H_(2)-TPR and TEM analysis proved that smaller CuO particles were formed and the dispersion of Cu on the surface of 13X zeolite was improved via the induction of ammonia.Evaluation on H_(2)S adsorption performance of the adsorbent was carried out using simulated BFG,and the results showed that NH_(3)–CuO/13X-3 has better breakthrough sulfur capacity,which was more than twice the sulfur capacity of CuO/13X.It is proposed that the enhanced desulfurization performance of NH_(3)–CuO/13X is attributed to an abundant pore of 13X,and combined action of 13X and CuO.This work provided an effective way to improve the sulfur capacity of zeolite-based adsorbents via impregnation method by ammonia induction.展开更多
基金supports from National Natural Science Foundation of China(Nos.22178059 and 91934301)Natural Science Foundation of Fujian Province,China(2020J01513)+1 种基金Sinochem Quanzhou Energy Technology Co.,Ltd.(ZHQZKJ-19-F-ZS-0076)Qingyuan Innovation Laboratory(No.00121002),and Fujian Hundred Talent Program.
文摘The nature and distribution of Cu species in Cu-SSZ-13 play a vital role in selective catalytic reduction of NO by NH3(NH3-SCR),but existing methods for adjusting the Cu distribution are complex and difficult to control.Herein,we report a simple and effective ion-exchange approach to regulate the Cu distribution in the one-pot synthesized Cu-SSZ-13 that possesses sufficient initial Cu species and thus provides a“natural environment”for adjusting Cu distribution precisely.By using this proposed strategy,a series of Cu-SSZ-13x zeolites with different Cu contents and distributions were obtained.It is shown that the dealumination of the as-synthesized Cu-SSZ-13 during the ion-exchange generates abundant vacant sites in the double six-membered-rings of the SSZ-13 zeolite for relocating Cu2+species and thus allows the redistribution of the Cu species.The catalytic results showed that the ion-exchanged Cu-SSZ-13 zeolites exhibit quite different catalytic performance in NH3-SCR reaction but superior to the parent counterpart.The structure–activity relationship analysis indicates that the redistribution of Cu species rather than other factors(e.g.,crystallinity,chemical composition,and porous structure)is responsible for the improved NH3-SCR performance and SO_(2) and H_(2)O resistance.Our work offers an effective method to precisely adjust the Cu distribution in preparing the industrial SCR catalysts.
基金the National Natural Science Foundation of China(nos.21621001,21835002,and 21920102005)the 111 Project(no.B17020)for supporting this work.
文摘Honeycomb cordierite coated with Cu-SSZ-13 zeolite is widely used for the selective catalytic reduction of NO_(x) with NH_(3)(NH_(3)-SCR)to reduce pollutants from vehicle emissions.However,conventional honeycomb catalysts fabricated via coating techniques are limited by low zeolite loadings,loss of the deposited zeolites,and complicated preparation processes.Herein,a facile,one-step three-dimensional(3D)printing strategy is developed to construct MnO_(x)/Cu-SSZ-13 monolithic catalysts with excellent catalytic performance for NH_(3)-SCR.Iron-containing halloysite nanotubes(Fe-HNTs)are introduced as printing ink additives to ensure mechanical stability and modulate the NH_(3)-SCR performance of monolithic catalysts in high temperature conditions.In situ incorporation of Mn into the Cu-SSZ-13 zeolite monoliths during the 3D printing process boosts the mechanical strength of the monolithic structures from 2.54 MPa to 4.33 MPa as well as broadens the temperature window(165-550℃)of the catalysts for NH_(3)-SCR with NO_(x) conversion of above 80%.Such robust multicomponent-integrated 3D-printed selfsupporting catalysts not only possess high zeolite loading and excellent catalytic activity,but also avoid complicated manufacturing processes,which contrasts with conventional honeycomb catalysts fabricated by extrusion coupled with coating.
基金Funded by the National Natural Science Foundation of China(No.50564043)
文摘A new type of zeolite composite antibacterial agents was prepared by introducing zinc oxide and copper ions into 13 X zeolite through the coprecipitation and ion-exchange methods. The structural properties of the tested antibacterial material were characterized and the antibacterial activity was evaluated. In Cu^(2+)/ZnO-13 X(CZ-13), zinc oxide and copper ions were either embedded in the interlayer space or dispersed on surface of 13 X zeolite. Excellent antimicrobial activity of CZ-13 was observed on Escherichia coli(E. coli) and Staphylococcus aureus(S.aureus). In the case of Cu^(2+)/ZnO-13 X, both MIC and MBC against E.coli were 0.2 mg/mL and 0.8 mg/mL. For S.aureus, CZ-13 also showed similar antibacterial properties. The bacterial cells turned from normal rod-shape into irregular shapes after treatment with the tested CZ-13. An increase of the intracellular enzyme activity after CZ-13 addition suggested that the permeability of the cell membrane increased and bacteria were damaged.
基金financially supported by National Natural Science Foundation of China(Grant.22076189)National Key Research and Development Program of China(No.2023YFC3707003)the Joint Fund of Yulin University and Dalian National Laboratory for Clean Energy(Grant.YLU-DNL Fund 2022003).
文摘Blast furnace gas(BFG)is an important by-product energy for the iron and steel industry and has been widely used for heating or electricity generation.However,the undesirable contaminants in BFG(especially H_(2)S)generate harmful environmental emissions.The desulfurization of BFG is urgent for integrated steel plants due to the stringent ultra-low emission standards.Compared with other desulfurization materials,zeolite-based adsorbents represent a viable option with low costs and long service life.In this study,an ammonia-induced CuO modified 13X adsorbent(NH_(3)–CuO/13X)was prepared for H_(2)S removal from simulated BFG at low temperature.The XRD,H_(2)-TPR and TEM analysis proved that smaller CuO particles were formed and the dispersion of Cu on the surface of 13X zeolite was improved via the induction of ammonia.Evaluation on H_(2)S adsorption performance of the adsorbent was carried out using simulated BFG,and the results showed that NH_(3)–CuO/13X-3 has better breakthrough sulfur capacity,which was more than twice the sulfur capacity of CuO/13X.It is proposed that the enhanced desulfurization performance of NH_(3)–CuO/13X is attributed to an abundant pore of 13X,and combined action of 13X and CuO.This work provided an effective way to improve the sulfur capacity of zeolite-based adsorbents via impregnation method by ammonia induction.
