Y zeolite supporting noble metal catalysts, as the important industrial catalysts for aromatics hydrogenation, have received increasing attention in recent years. Pd M/Y bimetallic catalysts, where M is non noble meta...Y zeolite supporting noble metal catalysts, as the important industrial catalysts for aromatics hydrogenation, have received increasing attention in recent years. Pd M/Y bimetallic catalysts, where M is non noble metal element, were prepared to investigate the effects of the addition of a second metal. Pd M/Y catalysts were evaluated under the following conditions: H 2 pressure 4.2 MPa, MHSV 4.0 h -1 , sulfur content in feed 3000 μg/g. The microreactor results indicated that the second metal remarkably affects the hydrogenation activity of Pd/Y catalysts. Among them, Cr and W improve the sulfur resistance of Pd/Y, but La, Mn, Mo and Ag make the sulfur resistance worse and the second metals have no evident influence on product selectivity and acidic properties of the catalysts.展开更多
Developing highly active and selective catalysts for the hydrogenation of nitroarenes,an environmentally benign process to produce industrially important aniline intermediates,is highly desirable but very challenging....Developing highly active and selective catalysts for the hydrogenation of nitroarenes,an environmentally benign process to produce industrially important aniline intermediates,is highly desirable but very challenging.Pd catalysts are generally recognized as active but nonselective catalysts for this important reaction.Here,we report an effective strategy to greatly improve the selectivity of Pd catalysts based on the reactive metal–support interaction.展开更多
The catalytic hydrogenation of nitroaromatics is an environmentally friendly technology for aniline production,and it is crucial to develop noble-metal-free catalysts that can achieve chemoselective hydrogenation of n...The catalytic hydrogenation of nitroaromatics is an environmentally friendly technology for aniline production,and it is crucial to develop noble-metal-free catalysts that can achieve chemoselective hydrogenation of nitroaromatics under mild reaction conditions.In this work,zinc-modified Ni-Ti catalysts(Ni_(x)Zn_(y)Ti_(1))were fabricated and applied for the hydrogenation of nitroaromatics hydrogenation.It was found that the introduction of zinc effectively increases the surface Ni density,enhances the electronic effect,and improves the interaction between Ni and TiO_(2),resulting in smaller Ni particle size,more oxygen vacancies,higher dispersion and greater concentration of Ni on the catalyst surface.Furthermore,the electron-rich Ni^(δ-) obtained by electron transfer from Zn and Ti to Ni effectively adsorbs and dissociates hydrogen.The results reveal that Ni_(x)Zn_(y)Ti_(1)(Ni_(0.5)Zn_(0.5)Ti_(1))shows excellent catalytic performance under mild conditions(70℃and 6 bar).These findings provide a rational strategy for the development of highly active non-noble-metal hydrogenation catalysts.展开更多
Catalytically-grown carbon nanofibers of two different conformations, fishbone and parallel types of the arrangement of carbon layers, were employed as the support of Pd-Pt metal catalysts for the hydrogenation of nap...Catalytically-grown carbon nanofibers of two different conformations, fishbone and parallel types of the arrangement of carbon layers, were employed as the support of Pd-Pt metal catalysts for the hydrogenation of naphthalene to tetralin. The sulfur tolerance of the catalyst system was investigated with the addition of 0.05% thiophene to the reactant of naphthalene in the process. The dispersion of Pd-Pt metal particles on the support was observed with a HREM and a pulsed hydrogen chemisorption method. The hydrogenation reaction of naphthalene was carried out in a CSTR at 250℃ and with the hydrogen pressure of 6 MPa. The results showed that the Pd-Pt catalyst supported on the carbon nanofibers was active in the process. The Pd-Pt metal catalyst supported on the parallel carbon nanofibers showed a higher sulfur tolerance than that on the fishbone carbon nanofibers. The reason may be attributed to their different conformations of the carbon layers, which leads to the different interaction of carbon layers with the supported metal particles.展开更多
文摘Y zeolite supporting noble metal catalysts, as the important industrial catalysts for aromatics hydrogenation, have received increasing attention in recent years. Pd M/Y bimetallic catalysts, where M is non noble metal element, were prepared to investigate the effects of the addition of a second metal. Pd M/Y catalysts were evaluated under the following conditions: H 2 pressure 4.2 MPa, MHSV 4.0 h -1 , sulfur content in feed 3000 μg/g. The microreactor results indicated that the second metal remarkably affects the hydrogenation activity of Pd/Y catalysts. Among them, Cr and W improve the sulfur resistance of Pd/Y, but La, Mn, Mo and Ag make the sulfur resistance worse and the second metals have no evident influence on product selectivity and acidic properties of the catalysts.
基金funding support from the National Natural Science Foundation of China(grant nos.U1932213,21431006,51732011,and 21761132008)the Foundation for Innovative Research Groups of the National Natural Sci-ence Foundationof China(grant no.21521001)+4 种基金and the Key Research Program of Frontier Sciences,CAS(grant no.QYZDJ-SSW-SLH036).H.W.L.is thankful for the support by the National Key Research and Development Program of China(no.2018YFA0702001)and the Fundamental Re-search Funds for the Central Universities(no.WK206-0190103).Z.Y.W.acknowledges the funding support from the National Natural Science Foundation of China(grant no.21703229)C.Q.H acknowledges the funding support from the Zhejiang Provincial Natural Science Foundation of Chi-na(grant no.LQ20B030008).W.X.L acknowledges the funding support from the National Natural Science Foun-dation of China(grant nos.91645202 and 91945302)the Key Research Programof Frontier Sciences,CAS(grantno.QYZDJ-SSW-SLH054)and the National Key Research and Development Program of China(grant nos.2018YFA-0208603 and 2017YFB0602205)partially carried out at the USTC Center for Micro and Nanoscale Research and Fabrication.
文摘Developing highly active and selective catalysts for the hydrogenation of nitroarenes,an environmentally benign process to produce industrially important aniline intermediates,is highly desirable but very challenging.Pd catalysts are generally recognized as active but nonselective catalysts for this important reaction.Here,we report an effective strategy to greatly improve the selectivity of Pd catalysts based on the reactive metal–support interaction.
基金supported by the National Natural Science Foundation of China(Grant Nos.22078277,21908185)Project of Hunan Provincial Education Department(Grant Nos.19B572,20B547)the Collaborative Innovation Center of New Chemical Technolo gies Technolo gies for Environmental Benignity and Efficient Resource Utilization,and the National Department of Education Engineering Research Centre for Chemical Process Simulation and Optimization。
文摘The catalytic hydrogenation of nitroaromatics is an environmentally friendly technology for aniline production,and it is crucial to develop noble-metal-free catalysts that can achieve chemoselective hydrogenation of nitroaromatics under mild reaction conditions.In this work,zinc-modified Ni-Ti catalysts(Ni_(x)Zn_(y)Ti_(1))were fabricated and applied for the hydrogenation of nitroaromatics hydrogenation.It was found that the introduction of zinc effectively increases the surface Ni density,enhances the electronic effect,and improves the interaction between Ni and TiO_(2),resulting in smaller Ni particle size,more oxygen vacancies,higher dispersion and greater concentration of Ni on the catalyst surface.Furthermore,the electron-rich Ni^(δ-) obtained by electron transfer from Zn and Ti to Ni effectively adsorbs and dissociates hydrogen.The results reveal that Ni_(x)Zn_(y)Ti_(1)(Ni_(0.5)Zn_(0.5)Ti_(1))shows excellent catalytic performance under mild conditions(70℃and 6 bar).These findings provide a rational strategy for the development of highly active non-noble-metal hydrogenation catalysts.
文摘Catalytically-grown carbon nanofibers of two different conformations, fishbone and parallel types of the arrangement of carbon layers, were employed as the support of Pd-Pt metal catalysts for the hydrogenation of naphthalene to tetralin. The sulfur tolerance of the catalyst system was investigated with the addition of 0.05% thiophene to the reactant of naphthalene in the process. The dispersion of Pd-Pt metal particles on the support was observed with a HREM and a pulsed hydrogen chemisorption method. The hydrogenation reaction of naphthalene was carried out in a CSTR at 250℃ and with the hydrogen pressure of 6 MPa. The results showed that the Pd-Pt catalyst supported on the carbon nanofibers was active in the process. The Pd-Pt metal catalyst supported on the parallel carbon nanofibers showed a higher sulfur tolerance than that on the fishbone carbon nanofibers. The reason may be attributed to their different conformations of the carbon layers, which leads to the different interaction of carbon layers with the supported metal particles.
