Ethanol induced method was applied to prepare Cu-Fe-Zr catalysts for conversion of syngas to higher alcohols. The catalytic performance of the catalysts induced by ethanol was superior to that of the catalyst prepared...Ethanol induced method was applied to prepare Cu-Fe-Zr catalysts for conversion of syngas to higher alcohols. The catalytic performance of the catalysts induced by ethanol was superior to that of the catalyst prepared by the conventional precipitation method. Among various procedures for ethanol induced method, it was found that incorporation of ethanol in the precipitation process was the better. After incorporation of ethanol, the crystal size of CuO decreased and the reduction of copper species became easier. The better activity of Cu-Fe-Zr catalysts prepared by ethanol induced procedures was probably caused by the higher dispersion of Cu species.展开更多
Direct conversion of syngas from those non-petroleum carbon resources to higher alcohols are very attractive due to the process simplicity with low energy consumption.However,the reaction always suffers from low yield...Direct conversion of syngas from those non-petroleum carbon resources to higher alcohols are very attractive due to the process simplicity with low energy consumption.However,the reaction always suffers from low yield as well as low selectivity.Herein,effective increase of higher alcohols proportion in the product is realized by direct conversion of syngas over electronically-modulated ZnO semiconductor via Cu doping.It is considered that the lower Fermi level and narrower band gap of catalysts by embedding Cu^(2+)into ZnO lattice could facilitate donor reaction by boosting the process for the reactants to obtain electrons on the catalyst surface for the formation of CH_(x) species and carbon chain growth,in which the Cu doping on ZnO lattice play important role in the promotion of CO adsorption.As a result,4 mol%Cu doped ZnO exhibits a highest C_(2+) OH/ROH fraction of 48.1%.Selectivity of catalysts from straight chain alcohol is better than from branch chain alcohol,which is different from promoted Cu/ZnO based catalyst.However,over-doping of Cu(7 mol%)on ZnO results in the aggregation Cu species on ZnO surface,leading to a sharp decrease of higher alcohols proportion to 3.2%.The results shed light on the nature that a direct correlation between semiconductor Fermi level and synthesis of higher alcohols,and the semiconductor-based catalysts mainly accelerate the hydrogenation reactions by enhancing thermally excited electron transfer.展开更多
In this paper, the molybdenum phosphide(MoP) catalysts(TPR-MoP and TPR-MoP-Pla) were prepared by the traditional method and the RF(radio frequency) thermal plasma technique respectively and characterized by x-ray diff...In this paper, the molybdenum phosphide(MoP) catalysts(TPR-MoP and TPR-MoP-Pla) were prepared by the traditional method and the RF(radio frequency) thermal plasma technique respectively and characterized by x-ray diffraction(XRD), x-ray photoelectron spectroscopy(XPS), transmission electron microscope(TEM), hydrogen temperature-programmed desorption(H_2-TPD) and carbon monoxide temperature-programmed desorption(CO-TPD) measurements,and their catalytic performance for HAS was evaluated. The results showed that the total and C_(2+) alcohols selectivity of the catalyst after plasma treatment(TPR-MoP-Pla) were enhanced.The enhanced catalytic performance could be related to more dislocation defects and the synergistic effect between Mo^(0–2+) and Mo^(4+) valence species in the TPR-MoP-Pla catalyst. In addition, this work suggests that thermal plasma treatment can be used as a new preparation technique for the synthesis of materials with rich species.展开更多
The production of higher terminal alcohols through CO hydrogenation according to the Fischer–Tropsch(F–T) process has been a topic of interest since the Institut Fran?ais du Pétrole(IFP) demonstrated shortchain...The production of higher terminal alcohols through CO hydrogenation according to the Fischer–Tropsch(F–T) process has been a topic of interest since the Institut Fran?ais du Pétrole(IFP) demonstrated shortchain C_1–C_6mixed alcohols production over cobalt–copper based catalysts. A number of catalyst formulations were screened for their suitability at that time. In particular, the addition of Cr, Zn, Al, Mn and V to Co Cu was investigated. In a number of patents, it was shown that catalyst preparation is crucial in these catalyst formulations and that high alcohols selectivity can only be achieved by carefully respecting the procedures and recipes. This short critical review highlights recent developments in Co Cu-based catalysts for higher terminal alcohols synthesis via F–T synthesis. Special attention will be given to catalyst preparation which according to developments in our group is based on oxalate precipitation. This way we show that the close association of Co and Cu on the one hand and promoter/dispersant on the other are of utmost importance to ensure high performance of the catalysts. We shall concentrate on 'Co Cu Mn','Co Cu Mo' and 'Co Cu Nb' catalyst formulations, all prepared via oxalate precipitation and combined with'entrainment techniques' if necessary, and show high total alcohols selectivity can be obtained with tunable Anderson-Schulz-Flory chain-lengthening probability. Either long-chain C_8–C_(14)terminal alcohols as feedstock for plasticizers, lubricants and detergents, or short-chain C_2–C_5alcohols as 'alkanol' fuels or fuel additives can be formed this way.展开更多
Cu-Co bi-metal catalysts derived from CuO/LaCoO3 perovskite structure were prepared by one-step citrate complexing method, and the structure evolution reaction from CuO/LaCoO3 to Cu-Co2C/La202CO3 under 1-12 pretreatme...Cu-Co bi-metal catalysts derived from CuO/LaCoO3 perovskite structure were prepared by one-step citrate complexing method, and the structure evolution reaction from CuO/LaCoO3 to Cu-Co2C/La202CO3 under 1-12 pretreatment was investigated by techniques of XRD, TPR and TEM. The results suggest that a much higher dispersion of copper significantly enhanced the reduction of cobalt, and a stronger interaction between copper and cobalt ions in LaCoO3 particles led to the formation of bi-metallic Cu-Co particles in the reduced catalysts and the enrichment of Co on the surface of bimetallic particles. The prepared catalysts were highly active and selective for the alcohol synthesis from syngas due to the presence of copper-modified C02C species.展开更多
Cu-Fe composite oxides were prepared by co-precipitation method and tested for higher alcohol synthesis from syngas. The selectivity to C2+OH and C6+OH in alcohol distribution was very high while the methane product...Cu-Fe composite oxides were prepared by co-precipitation method and tested for higher alcohol synthesis from syngas. The selectivity to C2+OH and C6+OH in alcohol distribution was very high while the methane product fraction in hydrocarbon distribution was rather low, demonstrating a promising potential in higher alcohols synthesis from syngas. The distribution of alcohols and hydrocarbons approximately obeyed Anderson-Schulz-Flory distribution with similar chain growth probability, indicating alcohols and hydrocarbons derived from the same intermediates. The effects of Cu/Fe molar ratio, reaction temperature and gas hourly space velocity (GHSV) on catalytic performance were studied in detail. The sample with a Cu/Fe molar ratio of 10/1 exhibited the best catalytic performance. Higher reaction temperature accelerated water-gas-shift reaction and led to lower total alcohols selectivity. GHSV showed great effect on catalytic performance and higher GHSV increased the total alcohol selectivity, indicating there existed visible dehydration reaction of alcohol into hydrocarbon.展开更多
The new Cu-Co based (Cu/Co/Zn/Zr) catalysts for higher-alcohol synthesis were prepared using coprecipitation method, plasma enhanced method and reverse coprecipitation method under ultrasound irradiation. The cataly...The new Cu-Co based (Cu/Co/Zn/Zr) catalysts for higher-alcohol synthesis were prepared using coprecipitation method, plasma enhanced method and reverse coprecipitation method under ultrasound irradiation. The catalysts were investigated by the means of BET, SEM, XRD, H2-TPR and XPS. Catalytic properties of the catalysts prepared by various methods were examined using CO hydrogenation reaction. It was found that plasma enhanced method and reverse coprecipitation method under ultrasound irradiation were both effective in enhancing the catalytic properties of Cu/Co/Zn/Zr mixed oxides. The small particle size, high dispersion of active components, the improvement of specific surface area and surface contents of active phases could account for the excellent performance of the experimental Cu/Co/Zn/Zr catalysts.展开更多
Two CuNiMnZrO_2 catalysts (crystallized or non-crystallized) were prepared byco-hydrolyzing zirconium n-propoxide with Cu(NO_3)_2, Mn(NO_3)_2 and Ni(NO_3)_2 in an ethanolsolution in the presence of diglycol. The physi...Two CuNiMnZrO_2 catalysts (crystallized or non-crystallized) were prepared byco-hydrolyzing zirconium n-propoxide with Cu(NO_3)_2, Mn(NO_3)_2 and Ni(NO_3)_2 in an ethanolsolution in the presence of diglycol. The physical and chemical properties of the catalysts werecharacterized using BET, XRD, TEM, XPS and CO-DRIFT techniques. It was found that thenon-crystallized CuNiMnZrO_2 catalyst demonstrated highly dispersed active phases and high activityfor CO adsorption, which resulted in good performance for synthesis of higher alcohols in COhydrogenation compared to crystallized CuNiMnZrO_2.展开更多
Higher alcohol synthesis(HAS)from syngas could efficiently alleviate the dependence on the traditional fossil resources.However,it is still challenging to construct high-performance HAS catalysts with satisfying selec...Higher alcohol synthesis(HAS)from syngas could efficiently alleviate the dependence on the traditional fossil resources.However,it is still challenging to construct high-performance HAS catalysts with satisfying selectivity,space–time yield(STY),and stability.Herein,we designed a diatomic catalyst by anchoring Co and Cu sites onto a hierarchical porous N-doped carbon matrix(Co/Cu–N–C).The Co/Cu–N–C is efficient for HAS and is among the best catalysts reported.With a COconversion of 81.7%,C2+OHselectivity could reach 58.5%with an outstanding C2+OH STY of 851.8 mg/g·h.We found that the N4–Co1 and Cu1–N4 showed an excellent synergistic effect.The adsorption of CO occurred on the Co site,and the surrounding nitrogen sites served as a hydrogen reservoir for the CO reduction reactions to form CHxCo.Meanwhile,the Cu sites stabilized a CHOCu species to interact with CHxCo,facilitating a barrier-free formation of C2 species,which is responsible for the high selectivity of higher alcohols.展开更多
基金Natural Science Foundation of State Key Laboratory of Coal Conversion(No09-610)
文摘Ethanol induced method was applied to prepare Cu-Fe-Zr catalysts for conversion of syngas to higher alcohols. The catalytic performance of the catalysts induced by ethanol was superior to that of the catalyst prepared by the conventional precipitation method. Among various procedures for ethanol induced method, it was found that incorporation of ethanol in the precipitation process was the better. After incorporation of ethanol, the crystal size of CuO decreased and the reduction of copper species became easier. The better activity of Cu-Fe-Zr catalysts prepared by ethanol induced procedures was probably caused by the higher dispersion of Cu species.
基金support by the National Natural Science Foundation of China(21975173 and 21776195)the fund for Shanxi“1331 project”and Major Projects of Shanxi Province(201803D121043).
文摘Direct conversion of syngas from those non-petroleum carbon resources to higher alcohols are very attractive due to the process simplicity with low energy consumption.However,the reaction always suffers from low yield as well as low selectivity.Herein,effective increase of higher alcohols proportion in the product is realized by direct conversion of syngas over electronically-modulated ZnO semiconductor via Cu doping.It is considered that the lower Fermi level and narrower band gap of catalysts by embedding Cu^(2+)into ZnO lattice could facilitate donor reaction by boosting the process for the reactants to obtain electrons on the catalyst surface for the formation of CH_(x) species and carbon chain growth,in which the Cu doping on ZnO lattice play important role in the promotion of CO adsorption.As a result,4 mol%Cu doped ZnO exhibits a highest C_(2+) OH/ROH fraction of 48.1%.Selectivity of catalysts from straight chain alcohol is better than from branch chain alcohol,which is different from promoted Cu/ZnO based catalyst.However,over-doping of Cu(7 mol%)on ZnO results in the aggregation Cu species on ZnO surface,leading to a sharp decrease of higher alcohols proportion to 3.2%.The results shed light on the nature that a direct correlation between semiconductor Fermi level and synthesis of higher alcohols,and the semiconductor-based catalysts mainly accelerate the hydrogenation reactions by enhancing thermally excited electron transfer.
基金the National Natural Science Foundation of China (No. 21476118)Major Projects of Inner Mongolia Natural Science Foundation (2019ZD01)+2 种基金Inner Mongolia Science & Technology Plan (Nos. 30500515330303)Inner Mongolia Major Science and Technology Project (No. 21300-5193901)Prairie Excellence Innovation and Entrepreneurial Team of Inner Mongolia (No. 12000-12102413)。
文摘In this paper, the molybdenum phosphide(MoP) catalysts(TPR-MoP and TPR-MoP-Pla) were prepared by the traditional method and the RF(radio frequency) thermal plasma technique respectively and characterized by x-ray diffraction(XRD), x-ray photoelectron spectroscopy(XPS), transmission electron microscope(TEM), hydrogen temperature-programmed desorption(H_2-TPD) and carbon monoxide temperature-programmed desorption(CO-TPD) measurements,and their catalytic performance for HAS was evaluated. The results showed that the total and C_(2+) alcohols selectivity of the catalyst after plasma treatment(TPR-MoP-Pla) were enhanced.The enhanced catalytic performance could be related to more dislocation defects and the synergistic effect between Mo^(0–2+) and Mo^(4+) valence species in the TPR-MoP-Pla catalyst. In addition, this work suggests that thermal plasma treatment can be used as a new preparation technique for the synthesis of materials with rich species.
基金supported by the National Science Foundation under contract No.CBET-1438227
文摘The production of higher terminal alcohols through CO hydrogenation according to the Fischer–Tropsch(F–T) process has been a topic of interest since the Institut Fran?ais du Pétrole(IFP) demonstrated shortchain C_1–C_6mixed alcohols production over cobalt–copper based catalysts. A number of catalyst formulations were screened for their suitability at that time. In particular, the addition of Cr, Zn, Al, Mn and V to Co Cu was investigated. In a number of patents, it was shown that catalyst preparation is crucial in these catalyst formulations and that high alcohols selectivity can only be achieved by carefully respecting the procedures and recipes. This short critical review highlights recent developments in Co Cu-based catalysts for higher terminal alcohols synthesis via F–T synthesis. Special attention will be given to catalyst preparation which according to developments in our group is based on oxalate precipitation. This way we show that the close association of Co and Cu on the one hand and promoter/dispersant on the other are of utmost importance to ensure high performance of the catalysts. We shall concentrate on 'Co Cu Mn','Co Cu Mo' and 'Co Cu Nb' catalyst formulations, all prepared via oxalate precipitation and combined with'entrainment techniques' if necessary, and show high total alcohols selectivity can be obtained with tunable Anderson-Schulz-Flory chain-lengthening probability. Either long-chain C_8–C_(14)terminal alcohols as feedstock for plasticizers, lubricants and detergents, or short-chain C_2–C_5alcohols as 'alkanol' fuels or fuel additives can be formed this way.
基金supported by the Program for Scientific Research Innovation Team in Colleges and Universities of Shandong Provincethe Ph.D.Programs Foundation of Liaocheng University(No.31805)the NSF of China(21263011,21376170)
文摘Cu-Co bi-metal catalysts derived from CuO/LaCoO3 perovskite structure were prepared by one-step citrate complexing method, and the structure evolution reaction from CuO/LaCoO3 to Cu-Co2C/La202CO3 under 1-12 pretreatment was investigated by techniques of XRD, TPR and TEM. The results suggest that a much higher dispersion of copper significantly enhanced the reduction of cobalt, and a stronger interaction between copper and cobalt ions in LaCoO3 particles led to the formation of bi-metallic Cu-Co particles in the reduced catalysts and the enrichment of Co on the surface of bimetallic particles. The prepared catalysts were highly active and selective for the alcohol synthesis from syngas due to the presence of copper-modified C02C species.
基金the State Key Fundamental Research Program(Ministry of Science and Technology of China,No.2011CBA00501)Shanghai Municipal Science and Technology Commission,China(Grant No:11DZ1200300)the Foundation of State Key Laboratory of Coal Conversion(Grant No:1112610)
文摘Cu-Fe composite oxides were prepared by co-precipitation method and tested for higher alcohol synthesis from syngas. The selectivity to C2+OH and C6+OH in alcohol distribution was very high while the methane product fraction in hydrocarbon distribution was rather low, demonstrating a promising potential in higher alcohols synthesis from syngas. The distribution of alcohols and hydrocarbons approximately obeyed Anderson-Schulz-Flory distribution with similar chain growth probability, indicating alcohols and hydrocarbons derived from the same intermediates. The effects of Cu/Fe molar ratio, reaction temperature and gas hourly space velocity (GHSV) on catalytic performance were studied in detail. The sample with a Cu/Fe molar ratio of 10/1 exhibited the best catalytic performance. Higher reaction temperature accelerated water-gas-shift reaction and led to lower total alcohols selectivity. GHSV showed great effect on catalytic performance and higher GHSV increased the total alcohol selectivity, indicating there existed visible dehydration reaction of alcohol into hydrocarbon.
基金supported by the National Natural Science Foundation of China(205903603)the New Century Excellent Talent Project of China(NCET-05-0783)
文摘The new Cu-Co based (Cu/Co/Zn/Zr) catalysts for higher-alcohol synthesis were prepared using coprecipitation method, plasma enhanced method and reverse coprecipitation method under ultrasound irradiation. The catalysts were investigated by the means of BET, SEM, XRD, H2-TPR and XPS. Catalytic properties of the catalysts prepared by various methods were examined using CO hydrogenation reaction. It was found that plasma enhanced method and reverse coprecipitation method under ultrasound irradiation were both effective in enhancing the catalytic properties of Cu/Co/Zn/Zr mixed oxides. The small particle size, high dispersion of active components, the improvement of specific surface area and surface contents of active phases could account for the excellent performance of the experimental Cu/Co/Zn/Zr catalysts.
基金This work was supported by the State Key Foundation Project for Development and Research of China(G1999022400)the Knowledge Innovation Program of CAS(KGCX2-302).
文摘Two CuNiMnZrO_2 catalysts (crystallized or non-crystallized) were prepared byco-hydrolyzing zirconium n-propoxide with Cu(NO_3)_2, Mn(NO_3)_2 and Ni(NO_3)_2 in an ethanolsolution in the presence of diglycol. The physical and chemical properties of the catalysts werecharacterized using BET, XRD, TEM, XPS and CO-DRIFT techniques. It was found that thenon-crystallized CuNiMnZrO_2 catalyst demonstrated highly dispersed active phases and high activityfor CO adsorption, which resulted in good performance for synthesis of higher alcohols in COhydrogenation compared to crystallized CuNiMnZrO_2.
基金the National Key Research and Development Program of China(grant nos.2019YFB1503903,2019YFB1503904,and 2018YFB1501403)The Natural Science Foundation of Fujian Province of China(grant no.2019J06005).
文摘Higher alcohol synthesis(HAS)from syngas could efficiently alleviate the dependence on the traditional fossil resources.However,it is still challenging to construct high-performance HAS catalysts with satisfying selectivity,space–time yield(STY),and stability.Herein,we designed a diatomic catalyst by anchoring Co and Cu sites onto a hierarchical porous N-doped carbon matrix(Co/Cu–N–C).The Co/Cu–N–C is efficient for HAS and is among the best catalysts reported.With a COconversion of 81.7%,C2+OHselectivity could reach 58.5%with an outstanding C2+OH STY of 851.8 mg/g·h.We found that the N4–Co1 and Cu1–N4 showed an excellent synergistic effect.The adsorption of CO occurred on the Co site,and the surrounding nitrogen sites served as a hydrogen reservoir for the CO reduction reactions to form CHxCo.Meanwhile,the Cu sites stabilized a CHOCu species to interact with CHxCo,facilitating a barrier-free formation of C2 species,which is responsible for the high selectivity of higher alcohols.