Binary metal oxide（MnOx-A/TiO2）catalysts were prepared by adding the second metal to manganese oxides supported on titanium dioxide（TiO2）,where,A indicates Fe2O3,WO3,MoO3,and Cr2O3.Their catalytic activity,N2 sele...Binary metal oxide（MnOx-A/TiO2）catalysts were prepared by adding the second metal to manganese oxides supported on titanium dioxide（TiO2）,where,A indicates Fe2O3,WO3,MoO3,and Cr2O3.Their catalytic activity,N2 selectivity,and SO2 poisonous tolerance were investigated.The catalytic performance at low temperatures decreased in the following order：Mn-W/TiO2〉Mn-Fe/TiO2〉Mn-Cr/TiO2〉Mn-Mo/TiO2,whereas the N2 selectivity decreased in the order：Mn-Fe/TiO2〉Mn-W/TiO2〉Mn-Mo/TiO2〉Mn-Cr/TiO2.In the presence of 0.01%SO2 and 6%H2O,the NOx conversions in the presence of Mn-W/TiO2,Mn-Fe/TiO2,or Mn-Mo/TiO2 maintain 98.5%,95.8%and 94.2%, respectively,after 8 h at 120°C at GHSV 12600 h？ 1 .As effective promoters,WO3 and Fe2O3 can increase N2 selectivity and the resistance to SO2 of MnOx/TiO2 significantly.The Fourier transform infrared（FTIR）spectra of NH3 over WO3 show the presence of Lewis acid sites.The results suggest that WO3 is the best promoter of MnOx/TiO2,and Mn-W/TiO2 is one of the most active catalysts for the low temperature selective catalytic reduction of NO with NH3.展开更多
TiO_2 modified Al_2O_3 binary oxide was prepared by a wet-impregnation method and used as the support for ruthenium catalyst. The catalytic performance of Ru/TiO_2–Al_2O_3catalyst in CO_2 methanation reaction was inv...TiO_2 modified Al_2O_3 binary oxide was prepared by a wet-impregnation method and used as the support for ruthenium catalyst. The catalytic performance of Ru/TiO_2–Al_2O_3catalyst in CO_2 methanation reaction was investigated. Compared with Ru/Al_2O_3 catalyst, the Ru/TiO_2–Al_2O_3catalytic system exhibited a much higher activity in CO_2 methanation reaction. The reaction rate over Ru/TiO_2–Al_2O_3 was 0.59 mol CO_2·(g Ru)1·h-1, 3.1 times higher than that on Ru/Al_2O_3[0.19 mol CO_2·(gRu)-1·h-1]. The effect of TiO_2 content and TiO_2–Al_2O_3calcination temperature on catalytic performance was addressed. The corresponding structures of each catalyst were characterized by means of H_2-TPR, XRD, and TEM. Results indicated that the averaged particle size of the Ru on TiO_2–Al_2O_3support is 2.8 nm, smaller than that on Al_2O_3 support of 4.3 nm. Therefore, we conclude that the improved activity over Ru/TiO_2–Al_2O_3catalyst is originated from the smaller particle size of ruthenium resulting from a strong interaction between Ru and the rutile-TiO_2 support, which hindered the aggregation of Ru nanoparticles.展开更多
The effect of acid component including various conventional acids and tungstic compounds on glucose hydrogenation over a series of binary catalyst system containing Ru/C catalyst was investigated. The results showed t...The effect of acid component including various conventional acids and tungstic compounds on glucose hydrogenation over a series of binary catalyst system containing Ru/C catalyst was investigated. The results showed that HC1, H2SO4, H3BO3, H3PO4, and HNO3 had negligible effect, while all the tungstic compounds imposed inhibiting effects on the hydrogenation of glucose over Ru/C catalyst, and the suppressing effect followed the order of H2WO4〉HPW〉WO3〉AMT〉HSiW. This order is the same as the order of ethylene glycol （EG） yields in the one-pot conversion of glucose to EG, suggesting the important role of competition between glucose hydrogenation and retro-aldol condensation in controlling the selectivity of EG.展开更多
In view of the dearth of active components and the unsatisfactory dispersion of Cu-based catalysts,it is imperative to undertake a detailed investigation of catalysts with enhanced catalytic performance.In order to ac...In view of the dearth of active components and the unsatisfactory dispersion of Cu-based catalysts,it is imperative to undertake a detailed investigation of catalysts with enhanced catalytic performance.In order to achieve a balance between the catalytic activity and stability in the reaction process,a series of P-atom doped Cu^(0)/Cu^(δ+)binary Cu-based catalysts were prepared by means of heteroatom introduction and heat treatment.The introduction of P enhanced the stability of Cu during heat treatment,thereby inhibiting the excessive agglomeration of Cu.The structure of the Cu^(0)/Cu^(δ+)binary catalyst was modified through heat treatment and HCl activation,and the relationship between its structure and catalytic activity was subsequently investigated.The activation process of HCl facilitated the conversion of the Cu^(0)state to the Cu-Cl state and augmented the valence state of Cu.The valence modulation of the Cu site by HCl during the reaction prevented the over-reduction of the Cu site by acetylene and enhanced the stability of the catalyst.The 3Cu/5Cu P/AC-800 catalyst was operated for 50 h without significant deactivation under the reaction conditions of T=180°C,V(HCl)/V(C_(2)H_(2))=1.15 and GHSV(C_(2)H_(2))=180 h^(-1).This design strategy provides a novel reference point for further studies of Cu Cl_(2)based catalysts for acetylene hydrochlorination.展开更多
A novel hydrocracking Ni-W binary catalyst was tentatively designed and prepared by means ofimpregnation on mixed supports of modified Y zeolite and amorphous aluminosilicate . The structure andproperties of catalyst ...A novel hydrocracking Ni-W binary catalyst was tentatively designed and prepared by means ofimpregnation on mixed supports of modified Y zeolite and amorphous aluminosilicate . The structure andproperties of catalyst were extensively characterized by XRD, NH3-TPD, IR and XRF techniques. The perfor-mance of catalyst was evaluated by a 100-ml hydrogenation laboratory test unit with two single-stage fixed-bedreactors connected in series. The characterization results showed that the catalyst has a developed and con-centrated mesopores distribution, suitable acid sites and acid strength distribution, and uniform and highdispersion of metal sites. Under a high conversion rate of 73.8% with the >350℃ feedstock, a 98.1m% of C5+yield and 83.5% of middle distillates selectivity were obtained. The yield of middle distillates boiling between140℃and 370℃ was 68.70m% and its quality could meet the WWFC category III specification. It means thatthis catalyst could be used to produce more high quality clean middle distillates derived from heavy oilhydrocracking. The potential aromatic content of heavy naphtha from 65℃ to 140℃ was 37.5m%. The BMCIvalue of >370℃ tail oil was 6.6. The heavy naphtha and tail oil are premium feedstocks for catalytic reformingand steam cracker units.展开更多
A series of carbon-based binary single-atom catalysts of Fe and Ni coordinated by nitrogen are fabricated using a glucose-chelating method.Depending on the Ni/Fe content,they exhibit a wide-range of controllable CO/H2...A series of carbon-based binary single-atom catalysts of Fe and Ni coordinated by nitrogen are fabricated using a glucose-chelating method.Depending on the Ni/Fe content,they exhibit a wide-range of controllable CO/H2 ratio from 0.14 to 10.86,which is meaningful to specific chemical processes.The durability of the catalyst is evaluated over an 8-hour period with no significant degradation of activity.The variation of the faradaic efficiency with Ni/Fe content is justified by density-functional-theory based calculation of the reaction barrier in both hydrogen evolution and CO2 reduction reactions.展开更多
Earth-abundant copper-tin(CuSn)electrocatalysts are potential candidates for cost-effective and sustainable production of CO from electrochemical carbon dioxide reduction(eCO_(2)R).However,the requirement of highoverp...Earth-abundant copper-tin(CuSn)electrocatalysts are potential candidates for cost-effective and sustainable production of CO from electrochemical carbon dioxide reduction(eCO_(2)R).However,the requirement of highoverpotential for obtaining reasonable current,low Faradaic efficiencies(FE)and low intrinsic catalytic activities require the optimisation of the CuSn nanoarchitecture for the further advancement in the field.In the current work,we have optimised Sn loading on Cu gas diffusion electrodes(GDEs)by electrochemical spontaneous precipitation.Samples with various Sn loadings were tested in a three-chamber GDE reactor to evaluate their CO_(2)reduction performances.The best performance of 92%CO Faradaic efficiency at a cathodic current density of 120 mA cm^(-2)was obtained from the 20 min Sn deposited Cu_(2)O sample operated at-1.13 V vs.RHE.The electrocatalyst had~13%surface coverage of Sn on Cu GDE surface,and had Sn in oxide form and copper in metallic form.The catalyst also showed stable performance and was operable for>3 h under chronoamperometric conditions.The surface of the GDE reduces from Cu2O to Cu during eCO_(2)R and goes further reconstruction during the eCO_(2)R.This study demonstrates the potential of Cu-Sn for selective CO production at high current densities.展开更多
文摘Binary metal oxide（MnOx-A/TiO2）catalysts were prepared by adding the second metal to manganese oxides supported on titanium dioxide（TiO2）,where,A indicates Fe2O3,WO3,MoO3,and Cr2O3.Their catalytic activity,N2 selectivity,and SO2 poisonous tolerance were investigated.The catalytic performance at low temperatures decreased in the following order：Mn-W/TiO2〉Mn-Fe/TiO2〉Mn-Cr/TiO2〉Mn-Mo/TiO2,whereas the N2 selectivity decreased in the order：Mn-Fe/TiO2〉Mn-W/TiO2〉Mn-Mo/TiO2〉Mn-Cr/TiO2.In the presence of 0.01%SO2 and 6%H2O,the NOx conversions in the presence of Mn-W/TiO2,Mn-Fe/TiO2,or Mn-Mo/TiO2 maintain 98.5%,95.8%and 94.2%, respectively,after 8 h at 120°C at GHSV 12600 h？ 1 .As effective promoters,WO3 and Fe2O3 can increase N2 selectivity and the resistance to SO2 of MnOx/TiO2 significantly.The Fourier transform infrared（FTIR）spectra of NH3 over WO3 show the presence of Lewis acid sites.The results suggest that WO3 is the best promoter of MnOx/TiO2,and Mn-W/TiO2 is one of the most active catalysts for the low temperature selective catalytic reduction of NO with NH3.
基金Supported by the National Natural Science Foundation of China(211031735127108721476226 and 51471076)DICP Fundamental Research Program for Clean Energy(DICPM201307)
文摘TiO_2 modified Al_2O_3 binary oxide was prepared by a wet-impregnation method and used as the support for ruthenium catalyst. The catalytic performance of Ru/TiO_2–Al_2O_3catalyst in CO_2 methanation reaction was investigated. Compared with Ru/Al_2O_3 catalyst, the Ru/TiO_2–Al_2O_3catalytic system exhibited a much higher activity in CO_2 methanation reaction. The reaction rate over Ru/TiO_2–Al_2O_3 was 0.59 mol CO_2·(g Ru)1·h-1, 3.1 times higher than that on Ru/Al_2O_3[0.19 mol CO_2·(gRu)-1·h-1]. The effect of TiO_2 content and TiO_2–Al_2O_3calcination temperature on catalytic performance was addressed. The corresponding structures of each catalyst were characterized by means of H_2-TPR, XRD, and TEM. Results indicated that the averaged particle size of the Ru on TiO_2–Al_2O_3support is 2.8 nm, smaller than that on Al_2O_3 support of 4.3 nm. Therefore, we conclude that the improved activity over Ru/TiO_2–Al_2O_3catalyst is originated from the smaller particle size of ruthenium resulting from a strong interaction between Ru and the rutile-TiO_2 support, which hindered the aggregation of Ru nanoparticles.
基金supported by the National Natural Science Foundation of China(Grants 21176235 and 21206159)
文摘The effect of acid component including various conventional acids and tungstic compounds on glucose hydrogenation over a series of binary catalyst system containing Ru/C catalyst was investigated. The results showed that HC1, H2SO4, H3BO3, H3PO4, and HNO3 had negligible effect, while all the tungstic compounds imposed inhibiting effects on the hydrogenation of glucose over Ru/C catalyst, and the suppressing effect followed the order of H2WO4〉HPW〉WO3〉AMT〉HSiW. This order is the same as the order of ethylene glycol （EG） yields in the one-pot conversion of glucose to EG, suggesting the important role of competition between glucose hydrogenation and retro-aldol condensation in controlling the selectivity of EG.
基金supported by the National Natural Science Foundation of China(No.22062021)the Science and Technology Project of Xinjiang supported by Central Government(No.2022BC001)+3 种基金Science and Technology Planning Project(No.2024AB048)Tianshan Talents Training Program of Xinjiang(Science and Technology Innovation Team,No.CZ002701)the Start-Up Foundation for high-level professionals of Shihezi University(No.RCZK201932)2024 Talent Development Fund-Tianchi Young Doctor of Excellence(No.CZ002744)。
文摘In view of the dearth of active components and the unsatisfactory dispersion of Cu-based catalysts,it is imperative to undertake a detailed investigation of catalysts with enhanced catalytic performance.In order to achieve a balance between the catalytic activity and stability in the reaction process,a series of P-atom doped Cu^(0)/Cu^(δ+)binary Cu-based catalysts were prepared by means of heteroatom introduction and heat treatment.The introduction of P enhanced the stability of Cu during heat treatment,thereby inhibiting the excessive agglomeration of Cu.The structure of the Cu^(0)/Cu^(δ+)binary catalyst was modified through heat treatment and HCl activation,and the relationship between its structure and catalytic activity was subsequently investigated.The activation process of HCl facilitated the conversion of the Cu^(0)state to the Cu-Cl state and augmented the valence state of Cu.The valence modulation of the Cu site by HCl during the reaction prevented the over-reduction of the Cu site by acetylene and enhanced the stability of the catalyst.The 3Cu/5Cu P/AC-800 catalyst was operated for 50 h without significant deactivation under the reaction conditions of T=180°C,V(HCl)/V(C_(2)H_(2))=1.15 and GHSV(C_(2)H_(2))=180 h^(-1).This design strategy provides a novel reference point for further studies of Cu Cl_(2)based catalysts for acetylene hydrochlorination.
文摘A novel hydrocracking Ni-W binary catalyst was tentatively designed and prepared by means ofimpregnation on mixed supports of modified Y zeolite and amorphous aluminosilicate . The structure andproperties of catalyst were extensively characterized by XRD, NH3-TPD, IR and XRF techniques. The perfor-mance of catalyst was evaluated by a 100-ml hydrogenation laboratory test unit with two single-stage fixed-bedreactors connected in series. The characterization results showed that the catalyst has a developed and con-centrated mesopores distribution, suitable acid sites and acid strength distribution, and uniform and highdispersion of metal sites. Under a high conversion rate of 73.8% with the >350℃ feedstock, a 98.1m% of C5+yield and 83.5% of middle distillates selectivity were obtained. The yield of middle distillates boiling between140℃and 370℃ was 68.70m% and its quality could meet the WWFC category III specification. It means thatthis catalyst could be used to produce more high quality clean middle distillates derived from heavy oilhydrocracking. The potential aromatic content of heavy naphtha from 65℃ to 140℃ was 37.5m%. The BMCIvalue of >370℃ tail oil was 6.6. The heavy naphtha and tail oil are premium feedstocks for catalytic reformingand steam cracker units.
基金This work was financially supported by the Natural Science Foundation of Tianjin,China(No.18JCYBJC20600)Institute of Energy,Hefei Comprehensive National Science Center(No.19KZS207).
文摘A series of carbon-based binary single-atom catalysts of Fe and Ni coordinated by nitrogen are fabricated using a glucose-chelating method.Depending on the Ni/Fe content,they exhibit a wide-range of controllable CO/H2 ratio from 0.14 to 10.86,which is meaningful to specific chemical processes.The durability of the catalyst is evaluated over an 8-hour period with no significant degradation of activity.The variation of the faradaic efficiency with Ni/Fe content is justified by density-functional-theory based calculation of the reaction barrier in both hydrogen evolution and CO2 reduction reactions.
基金The authors would like to acknowledge the support from the UKRI Interdisciplinary Centre for Circular Chemical Economy(EP/V011863/1)EPSRC LifesCO2R project(EP/N009746/1 EP/N009746/2)and EPSRC NECEM Energy Material Centre(EP/R021503/1)Loughborough Materials Characterisation Centre Pump Prime grant which enabled the access to the characterisation facilities is also acknowledged.
文摘Earth-abundant copper-tin(CuSn)electrocatalysts are potential candidates for cost-effective and sustainable production of CO from electrochemical carbon dioxide reduction(eCO_(2)R).However,the requirement of highoverpotential for obtaining reasonable current,low Faradaic efficiencies(FE)and low intrinsic catalytic activities require the optimisation of the CuSn nanoarchitecture for the further advancement in the field.In the current work,we have optimised Sn loading on Cu gas diffusion electrodes(GDEs)by electrochemical spontaneous precipitation.Samples with various Sn loadings were tested in a three-chamber GDE reactor to evaluate their CO_(2)reduction performances.The best performance of 92%CO Faradaic efficiency at a cathodic current density of 120 mA cm^(-2)was obtained from the 20 min Sn deposited Cu_(2)O sample operated at-1.13 V vs.RHE.The electrocatalyst had~13%surface coverage of Sn on Cu GDE surface,and had Sn in oxide form and copper in metallic form.The catalyst also showed stable performance and was operable for>3 h under chronoamperometric conditions.The surface of the GDE reduces from Cu2O to Cu during eCO_(2)R and goes further reconstruction during the eCO_(2)R.This study demonstrates the potential of Cu-Sn for selective CO production at high current densities.
