XPS and chemical trapping experments with H2, NH3, and CH3I as trapping agents were carried out for studying the adsorption of propylene over MoO3 or r-Bi2MoO6. The results show that the fragmentation of carbon chain ...XPS and chemical trapping experments with H2, NH3, and CH3I as trapping agents were carried out for studying the adsorption of propylene over MoO3 or r-Bi2MoO6. The results show that the fragmentation of carbon chain takes place during the adsorption of propylene through breaking C -C double bond and C-C bond on Mo2+ and the adjacent lattice oxygen, leading to formation of the oxygen- or nitrogen-containing by-products of C1 and C2 species. Diffuse-Reflection Fourier Transform Infrared (DRFTIR) Spectroscopy was used to study the surface species formed during the chemisorption and reaction of propylene over y-Bi2MoO6 at a lower temperature. The results that C1, C2 adspecies were detected by DRFTIR at 175℃ are consistent with the results of XPS and chemical trapping experiments, whlle the results at 50℃ Grasselli et al.展开更多
The most challenging goal of C1 chemistry is the control of C–C coupling to produce chemicals or fuels from C1 feedstocks,in particular syngas（H2/CO）,which can be derived from various carbon resources such as coal,...The most challenging goal of C1 chemistry is the control of C–C coupling to produce chemicals or fuels from C1 feedstocks,in particular syngas（H2/CO）,which can be derived from various carbon resources such as coal,natural gas or shale gas,and biomass.展开更多
Oxidative dehydrogenation of propane has been an ever-growing field for propylene production due to its exothermic properties,of which overoxidation is the major drawback,with CO and even CO_(2) as undesired by-produc...Oxidative dehydrogenation of propane has been an ever-growing field for propylene production due to its exothermic properties,of which overoxidation is the major drawback,with CO and even CO_(2) as undesired by-products.For the purpose of getting higher propylene selectivity as well as yield,herein,we report Ni single atoms supported on calcium aluminate as an efficient catalyst candidate for propane oxidative dehydrogenation.Beneficial from higher valence states of Ni1 species,it shows 2—3 times as much propylene selectivity as that of Ni nanoparticles.About 14.2%C_(3)H_(6) yield with 47.3%propylene selectivity has been achieved on Ni single atom catalyst and a good stability during 20 h test can be obtained as well.展开更多
The on-purpose direct propane dehydrogenation(PDH) has received extensive attention to meet the everincreasing demand of propylene.In this work,by means of density functional theory(DFT) calculations,we systematically...The on-purpose direct propane dehydrogenation(PDH) has received extensive attention to meet the everincreasing demand of propylene.In this work,by means of density functional theory(DFT) calculations,we systematically studied the intrinsic coordinating effect of Fe single-atom catalysts in PDH.Interestingly,the N and P dual-coordinated single Fe(Fe-N_(3)P-C) significantly outperform the Fe-N_(4-)C site in catalysis and exhibit desired activity and selectivity at industrial PDH temperatures.The mechanistic origin of different performance on Fe-N_(3)P-C and Fe-N_(4-)C has been ascribed to the geometric effect.To be specific,the in-plane configuration of Fe-N_(4) site exhibits low H affinity,which results in poor activity in C-H bond activations.By contrast,the out-of-plane structure of Fe-N_(3)P-C site exhibits moderate H affinity,which not only promote the C-H bond scission but also offer a platform for obtaining appropriate H diffusion rate which ensures the high selectivity of propylene and the regeneration of catalysts.This work demonstrates promising applications of dual-coordinated single-atom catalysts for highly selective propane dehydrogenation.展开更多
On-purpose propane dehydrogenation(PDH) has emerged as a profitable alternative to the traditional cracking of oil products for propylene production. By means of density functional theory(DFT) calculations, the presen...On-purpose propane dehydrogenation(PDH) has emerged as a profitable alternative to the traditional cracking of oil products for propylene production. By means of density functional theory(DFT) calculations, the present work demonstrates that Fe atoms may atomically disperse on MoS_(2)(Fe_(1)/MoS_(2)) and serve as a promising single-atom catalyst(SAC) for PDH. The catalytic activity of Fe_(1)/MoS_(2)is attributed to the highly exposed d orbitals of single Fe atoms, while the propylene selectivity is originated from the kinetic inhibition of propylene dehydrogenation resulting from fast propenyl hydrogenation. The unique catalytic selectivity of Fe_(1)/MoS_(2)may inspire further investigations of on-purpose dehydrogenations of propane on SACs.展开更多
基金Supported by the National Natural Science Fundation of China.
文摘XPS and chemical trapping experments with H2, NH3, and CH3I as trapping agents were carried out for studying the adsorption of propylene over MoO3 or r-Bi2MoO6. The results show that the fragmentation of carbon chain takes place during the adsorption of propylene through breaking C -C double bond and C-C bond on Mo2+ and the adjacent lattice oxygen, leading to formation of the oxygen- or nitrogen-containing by-products of C1 and C2 species. Diffuse-Reflection Fourier Transform Infrared (DRFTIR) Spectroscopy was used to study the surface species formed during the chemisorption and reaction of propylene over y-Bi2MoO6 at a lower temperature. The results that C1, C2 adspecies were detected by DRFTIR at 175℃ are consistent with the results of XPS and chemical trapping experiments, whlle the results at 50℃ Grasselli et al.
文摘The most challenging goal of C1 chemistry is the control of C–C coupling to produce chemicals or fuels from C1 feedstocks,in particular syngas（H2/CO）,which can be derived from various carbon resources such as coal,natural gas or shale gas,and biomass.
基金supported by the National Key Research and Development program of China(2021YFA1500503)the National Natural Science Foundation of China(21961142006,21972135)CAS Project for Young Scientists in Basic Research(YSBR-022).
文摘Oxidative dehydrogenation of propane has been an ever-growing field for propylene production due to its exothermic properties,of which overoxidation is the major drawback,with CO and even CO_(2) as undesired by-products.For the purpose of getting higher propylene selectivity as well as yield,herein,we report Ni single atoms supported on calcium aluminate as an efficient catalyst candidate for propane oxidative dehydrogenation.Beneficial from higher valence states of Ni1 species,it shows 2—3 times as much propylene selectivity as that of Ni nanoparticles.About 14.2%C_(3)H_(6) yield with 47.3%propylene selectivity has been achieved on Ni single atom catalyst and a good stability during 20 h test can be obtained as well.
基金support from National Science Foundation of China(Nos.21771134,22173067)National Key R&D Program of China(No.2017YFA0204800)+4 种基金Science and Technology Project of Jiangsu Province(No.BZ2020011)Collaborative Innovation Center of Suzhou Nano Science&Technologythe Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)the 111 Projectthe Science and Technology Development Fund,Macao SAR(FDCT No.0052/2021/A)。
文摘The on-purpose direct propane dehydrogenation(PDH) has received extensive attention to meet the everincreasing demand of propylene.In this work,by means of density functional theory(DFT) calculations,we systematically studied the intrinsic coordinating effect of Fe single-atom catalysts in PDH.Interestingly,the N and P dual-coordinated single Fe(Fe-N_(3)P-C) significantly outperform the Fe-N_(4-)C site in catalysis and exhibit desired activity and selectivity at industrial PDH temperatures.The mechanistic origin of different performance on Fe-N_(3)P-C and Fe-N_(4-)C has been ascribed to the geometric effect.To be specific,the in-plane configuration of Fe-N_(4) site exhibits low H affinity,which results in poor activity in C-H bond activations.By contrast,the out-of-plane structure of Fe-N_(3)P-C site exhibits moderate H affinity,which not only promote the C-H bond scission but also offer a platform for obtaining appropriate H diffusion rate which ensures the high selectivity of propylene and the regeneration of catalysts.This work demonstrates promising applications of dual-coordinated single-atom catalysts for highly selective propane dehydrogenation.
基金Natural Science Foundation of China (Nos. 21771134, 22173067)National Key R&D Program of China (Nos. 2017YFA0204800)+4 种基金Science and Technology Project of Jiangsu Province (No. BZ2020011)the Science and Technology Development Fund, Macao SAR (FDCT, No. 0052/2021/A)Collaborative Innovation Center of Suzhou Nano Science & Technology, the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)the 111 Projectsupport from Postgraduate Research & Practice Innovation Program of Jiangsu Province (No. KYCX20_2658)。
文摘On-purpose propane dehydrogenation(PDH) has emerged as a profitable alternative to the traditional cracking of oil products for propylene production. By means of density functional theory(DFT) calculations, the present work demonstrates that Fe atoms may atomically disperse on MoS_(2)(Fe_(1)/MoS_(2)) and serve as a promising single-atom catalyst(SAC) for PDH. The catalytic activity of Fe_(1)/MoS_(2)is attributed to the highly exposed d orbitals of single Fe atoms, while the propylene selectivity is originated from the kinetic inhibition of propylene dehydrogenation resulting from fast propenyl hydrogenation. The unique catalytic selectivity of Fe_(1)/MoS_(2)may inspire further investigations of on-purpose dehydrogenations of propane on SACs.
