Metal nanoparticle(NP_S)catalysts exhibit desirable activities in various catalytic reactions.However,the sintering of metal NPs at high-temperatures even in reducing atmospheres limits its practical application.In th...Metal nanoparticle(NP_S)catalysts exhibit desirable activities in various catalytic reactions.However,the sintering of metal NPs at high-temperatures even in reducing atmospheres limits its practical application.In this work,we successfully synthesized TPA-ZSM-5 with pit-type defects by treating the ZSM-5 with tetrahydroxy ammonium hydroxide(TPAOH),which was then used as a support to prepare Ag-based and Cu-based catalysts.Stability testing results show that the Ag/TPA-ZSM-5 catalyst treated at 800℃with H_(2) could maintain the high performance in NH_(3)-SCO and the Cu/TPA-ZSM-5 catalyst treated at 900℃ with N_(2) could maintained its excellent activity in NH_(3)-SCR,however,the activities of Ag/ZSM-5 and Cu/ZSM-5 were drastically decreased or even deactivated after high-temperature treatment.In addition,a series of characterization analyses revealed that the excellent thermal stability is attribute to the presence of pit-type defects in the TPA-ZSM-5 as physical barriers to slow down or even inhibit the Ag NPs and Cu NPs sintering process.The strategy of using the pit-type defects to inhibit the sintering of metal NPs and improve the thermal stability can greatly enhance the practical application of catalysts.展开更多
基金supported by the National Natural Science Foundation of China(No.52370113)Yunnan Fundamental Research Projects(No.202101BE070001-001)。
文摘Metal nanoparticle(NP_S)catalysts exhibit desirable activities in various catalytic reactions.However,the sintering of metal NPs at high-temperatures even in reducing atmospheres limits its practical application.In this work,we successfully synthesized TPA-ZSM-5 with pit-type defects by treating the ZSM-5 with tetrahydroxy ammonium hydroxide(TPAOH),which was then used as a support to prepare Ag-based and Cu-based catalysts.Stability testing results show that the Ag/TPA-ZSM-5 catalyst treated at 800℃with H_(2) could maintain the high performance in NH_(3)-SCO and the Cu/TPA-ZSM-5 catalyst treated at 900℃ with N_(2) could maintained its excellent activity in NH_(3)-SCR,however,the activities of Ag/ZSM-5 and Cu/ZSM-5 were drastically decreased or even deactivated after high-temperature treatment.In addition,a series of characterization analyses revealed that the excellent thermal stability is attribute to the presence of pit-type defects in the TPA-ZSM-5 as physical barriers to slow down or even inhibit the Ag NPs and Cu NPs sintering process.The strategy of using the pit-type defects to inhibit the sintering of metal NPs and improve the thermal stability can greatly enhance the practical application of catalysts.
