novel honeycomb-shaped Pt Sn Na/g-Al2 O3/cordierite monolithic catalyst（Pt 0.5%, Sn 0.9%, Na 1.0%,relative to Al2 O3 weight） was developed and its catalytic performances in propane dehydrogenation were tested and co...novel honeycomb-shaped Pt Sn Na/g-Al2 O3/cordierite monolithic catalyst（Pt 0.5%, Sn 0.9%, Na 1.0%,relative to Al2 O3 weight） was developed and its catalytic performances in propane dehydrogenation were tested and compared with the classical granule catalyst with same Pt, Sn and Na contents under the conditions of 0.1 MPa, 590C, C3 H8/H2 at 3/1（molar ratio） and gas hourly space velocity（GHSV） at155 h-1. Interestingly, despite the generated coke amount and exposed Pt fraction, the honey combshaped structure of monolithic catalyst exerted important influences on its catalytic activities and led to the advanced catalytic performances over the granule catalyst.展开更多
PtSnNa/γ-Al2O3 catalyst is widely used in the dehydrogenation of light alkane. This paper reports a new fabrication method of the catalyst. In the work, γ-Al2O3, SnCl4 and NaCl were ball milled to upload Sn and Na＋...PtSnNa/γ-Al2O3 catalyst is widely used in the dehydrogenation of light alkane. This paper reports a new fabrication method of the catalyst. In the work, γ-Al2O3, SnCl4 and NaCl were ball milled to upload Sn and Na＋ onto the support instead of the conventionally used immersion method. The subsequent baking procedures frimly fixed Sn onto the support, which could disperse Pt introduced by immersion. The effects of Sn and Na＋ additives on the catalytic performance of PtSnNa/y-Al2O3 catalyst were investigated. It was found that the appropriate molar ratio of Sn/Pt was 6：1 while the favorable weight percentage of Na＋ was 0.90%. Compared with the reaction catalyzed by the industrially employed PtSnNa/ γ-Al2O3 catalyst, the conversion of propane and the selectivity of propylene had been greatly improved, which were 26.97%; and 99.18% respectivelv after 12 h reaction.展开更多
Selective production of specific products,such as jet fuel,in Fischer-Tropsch synthesis(FTS)is a huge challenge due to the Anderson-Schulz-Flory(ASF)distribution law.Herein,by filling K-promoted Fe-based active specie...Selective production of specific products,such as jet fuel,in Fischer-Tropsch synthesis(FTS)is a huge challenge due to the Anderson-Schulz-Flory(ASF)distribution law.Herein,by filling K-promoted Fe-based active species,which usually produces medium-to-short chain hydrocarbons in high-temperature FTS,into the hierarchical carbon nanocages(hCNC),jet fuel with high selectivity of 60% is directly obtained in FTS at 300℃,exceeding the ASF maximum limitation of ca.41%.Through the theoretical simulations,we attribute this performance to the CO enrichment inside the nanocavities due to the sieving effect of the micropores across the hCNC shells(~6A)and the increased collision frequency in confined space.These two factors thereby promote the CO conversion and carbon-chain growth longer over the catalytically active Fe_(5)C_(2) phase,resulting in the remarkable selectivity to jet fuel.The effects of the length and size of micropores on the CO/H_(2) diffusion and FTS performance are examined,which corroborate the crucial role of micropores in the high-selective FTS to jet fuel.This work not only provides a remarkable catalyst to the selective jet fuel synthesis,but also offers an alternative way to design advanced catalysts for FTS.展开更多
Semihydrogenation of trace acetylene in an ethylene gas stream is a vital step for the industrial production of polyethylene,in which Pd single-site catalysts(SSCs)have great potential.Herein,two Pd SSCs with differen...Semihydrogenation of trace acetylene in an ethylene gas stream is a vital step for the industrial production of polyethylene,in which Pd single-site catalysts(SSCs)have great potential.Herein,two Pd SSCs with different coordination structures are prepared on hierarchical nitrogen-doped carbon nanocages(hNCNC)by regulating the nitrogen species with or without using dicyandiamide.With using dicyandiamide,the obtained Pd1-Ndicy/hNCNC SSC features the coordinated Pd by two pyridinic N and two pyrrolic N(PdN^(py)_(2)N^(pr)_(2)).Without using dicyandiamide,the obtained Pd1/hNCNC SSC features the coordinated Pd by pyridinic N and C(PdN^(py_(x)C_(4-x)),x=1-4).The former exhibits an 18-fold increase in catalytic activity compared to the latter.Theoretical results reveal the abundant unoccupied orbital states above the Fermi level of moiety,which can facilitate the activation of substrate molecules and dynamics of acetylene hydrogenation as supported by the combined theoretical and experimental results.In addition,PdN^(py)_(2)N^(pr)_(2)the moiety presents a favorable desorption of ethylene.Consequently,the Pd1-Ndicy/hNCNC SSC exhibits high C2H2 conversion(99%)and C2H4 selectivity(87%)at 160℃.This study demonstrates the impact of Pd single-site coordination structure on catalytic performance,which is significant for the rational design of advanced Pd SSCs on carbon-based supports.展开更多
基金Jiangsu Planned Projects for Postdoctoral Research Funds (No. 1301080C)Specialized Research Fund for the Doctoral Program of Higher Education (No. SRFDP-2012009111001)+1 种基金Key Science & Technology Specific Projects of Yangzhou (No. YZ20122029)Yangzhou Nature Science Foundation (No. YZ2014040) for financial support
文摘novel honeycomb-shaped Pt Sn Na/g-Al2 O3/cordierite monolithic catalyst（Pt 0.5%, Sn 0.9%, Na 1.0%,relative to Al2 O3 weight） was developed and its catalytic performances in propane dehydrogenation were tested and compared with the classical granule catalyst with same Pt, Sn and Na contents under the conditions of 0.1 MPa, 590C, C3 H8/H2 at 3/1（molar ratio） and gas hourly space velocity（GHSV） at155 h-1. Interestingly, despite the generated coke amount and exposed Pt fraction, the honey combshaped structure of monolithic catalyst exerted important influences on its catalytic activities and led to the advanced catalytic performances over the granule catalyst.
基金the Doctoral Program of Higher Education(No. SRFDP-2012009111001)NNSFC(No. 21202141)+1 种基金Priority Academic Program Development(PAPD) of Jiangsu Higher Education Institutions, Key Science & Technology Specific Projects of Yangzhou(No. YZ20122029)Yangzhou Nature Science Foundation(No. YZ2014040) for financial support
文摘PtSnNa/γ-Al2O3 catalyst is widely used in the dehydrogenation of light alkane. This paper reports a new fabrication method of the catalyst. In the work, γ-Al2O3, SnCl4 and NaCl were ball milled to upload Sn and Na＋ onto the support instead of the conventionally used immersion method. The subsequent baking procedures frimly fixed Sn onto the support, which could disperse Pt introduced by immersion. The effects of Sn and Na＋ additives on the catalytic performance of PtSnNa/y-Al2O3 catalyst were investigated. It was found that the appropriate molar ratio of Sn/Pt was 6：1 while the favorable weight percentage of Na＋ was 0.90%. Compared with the reaction catalyzed by the industrially employed PtSnNa/ γ-Al2O3 catalyst, the conversion of propane and the selectivity of propylene had been greatly improved, which were 26.97%; and 99.18% respectivelv after 12 h reaction.
基金jointly supported by the National Key Research and Development Program of China(No.2021YFA1500900)the National Natural Science Foundation of China(Nos.21972061 and 52071174)+1 种基金the Natural Science Foundation of Jiangsu Province,Major Project(No.BK20212005)the Foundation of Science and Technology of Suzhou(No.SYC2022102).
文摘Selective production of specific products,such as jet fuel,in Fischer-Tropsch synthesis(FTS)is a huge challenge due to the Anderson-Schulz-Flory(ASF)distribution law.Herein,by filling K-promoted Fe-based active species,which usually produces medium-to-short chain hydrocarbons in high-temperature FTS,into the hierarchical carbon nanocages(hCNC),jet fuel with high selectivity of 60% is directly obtained in FTS at 300℃,exceeding the ASF maximum limitation of ca.41%.Through the theoretical simulations,we attribute this performance to the CO enrichment inside the nanocavities due to the sieving effect of the micropores across the hCNC shells(~6A)and the increased collision frequency in confined space.These two factors thereby promote the CO conversion and carbon-chain growth longer over the catalytically active Fe_(5)C_(2) phase,resulting in the remarkable selectivity to jet fuel.The effects of the length and size of micropores on the CO/H_(2) diffusion and FTS performance are examined,which corroborate the crucial role of micropores in the high-selective FTS to jet fuel.This work not only provides a remarkable catalyst to the selective jet fuel synthesis,but also offers an alternative way to design advanced catalysts for FTS.
基金supported by the National Key Research and Development Program of China(No.2021YFA1500900)the National Natural Science Foundation of China(No.52071174)the Natural Science Foundation of Jiangsu Province,Major Project(No.BK20212005).
文摘Semihydrogenation of trace acetylene in an ethylene gas stream is a vital step for the industrial production of polyethylene,in which Pd single-site catalysts(SSCs)have great potential.Herein,two Pd SSCs with different coordination structures are prepared on hierarchical nitrogen-doped carbon nanocages(hNCNC)by regulating the nitrogen species with or without using dicyandiamide.With using dicyandiamide,the obtained Pd1-Ndicy/hNCNC SSC features the coordinated Pd by two pyridinic N and two pyrrolic N(PdN^(py)_(2)N^(pr)_(2)).Without using dicyandiamide,the obtained Pd1/hNCNC SSC features the coordinated Pd by pyridinic N and C(PdN^(py_(x)C_(4-x)),x=1-4).The former exhibits an 18-fold increase in catalytic activity compared to the latter.Theoretical results reveal the abundant unoccupied orbital states above the Fermi level of moiety,which can facilitate the activation of substrate molecules and dynamics of acetylene hydrogenation as supported by the combined theoretical and experimental results.In addition,PdN^(py)_(2)N^(pr)_(2)the moiety presents a favorable desorption of ethylene.Consequently,the Pd1-Ndicy/hNCNC SSC exhibits high C2H2 conversion(99%)and C2H4 selectivity(87%)at 160℃.This study demonstrates the impact of Pd single-site coordination structure on catalytic performance,which is significant for the rational design of advanced Pd SSCs on carbon-based supports.
