CaO-based sorbent is considered to be a promising candidate for capturing CO_2 at high temperature. However,the adsorption capacity of CaO decreases sharply with the increase of the carbonation/calcination cycles. In ...CaO-based sorbent is considered to be a promising candidate for capturing CO_2 at high temperature. However,the adsorption capacity of CaO decreases sharply with the increase of the carbonation/calcination cycles. In this study, CaO was derived from calcium acetate(CaAc_2), which was doped with different elements(Mg, Al,Ce, Zr and La) to improve the cyclic stability. The carbonation conversion and cyclic stability of sorbents were tested by thermogravimetric analyzer(TGA). The sorbents were characterized by N_2 isothermal adsorption measurements, scanning electron microscopy(SEM) and X-ray diffraction(XRD). The results showed that the cyclic stabilities of all modified sorbents were improved by doping elements, while the carbonation conversions of sorbents in the 1st cycle were not increased by doping different elements. After 22 cycles, the cyclic stabilities of CaO–Al, CaO–Ce and CaO–La were above 96.2%. After 110 cycles, the cyclic stability of CaO–Al was still as high as 87.1%. Furthermore, the carbonation conversion was closely related to the critical time and specific surface area.展开更多
Chemical conversion of carbon dioxide(CO2)to value-added useful chemicals like cyclic carbonates represents one potential solution to climate warming.Here,a kind of porous organic polymer(HAT-TP)with large surface are...Chemical conversion of carbon dioxide(CO2)to value-added useful chemicals like cyclic carbonates represents one potential solution to climate warming.Here,a kind of porous organic polymer(HAT-TP)with large surface area and excellent carbon dioxide uptake capacity is prepared via a condensation reaction to introduce hexaazatriphenylene(HAT)units into triptycene(TP)-based microporous polymer.HAT-TP can coordinate with zinc ions,and the resulting polymer(Zn/HAT-TP)can be utilized as an efficient recyclable catalyst for chemical conversion of CO2 into cyclic carbonates with epoxides.展开更多
Global warming caused by excess carbon dioxide(CO_(2))emission has been a focus of the world.The development of neutral carbon technologies becomes a strategic choice for the sustainable human society.Integrating CO_(...Global warming caused by excess carbon dioxide(CO_(2))emission has been a focus of the world.The development of neutral carbon technologies becomes a strategic choice for the sustainable human society.Integrating CO_(2) capture and conversion(iCCC)technology can simultaneously convert the captured CO_(2) from flue gas into value-added chemicals,which saves great energies and expenses incurred in CO_(2) compression and transportation processes of conventional carbon capture,utilization,and storage(CCUS)technology.The present review criti-cally discusses the dual-function materials(DFMs)and the iCCC technology at intermediate temperature for methane production and high temperature for syngas production.The design of reactor and optimization of operation conditions are emphasized from the perspective of industrial applications.The dual-fixed-bed reactors mode by switching the flue gas and reactant gases,and the dual-fluidized-bed reactors mode by the circulation of DFMs particles are comparatively reviewed.We hope this review can stimulate further studies including designing and fabricating feasible DFMs,exploring realistic catalytic process for CO_(2) conversion to high value-added chemicals,developing workable reactor modes and optimizing operation conditions,and establishing industrial demonstration for real applications of iCCC technology in the future.展开更多
The conversion of propargylic alcohols and carbon dioxide(CO_(2)) into fine chemicals suffers from issues of harsh reaction conditions and difficult catalyst recovery. To achieve efficient CO_(2)activation at low ener...The conversion of propargylic alcohols and carbon dioxide(CO_(2)) into fine chemicals suffers from issues of harsh reaction conditions and difficult catalyst recovery. To achieve efficient CO_(2)activation at low energy consumption, a silver-anchored porous aromatic framework catalyst Ag@PAF-DAB with high active phase density and CO_(2)adsorption capacity was proposed. Since Ag@PAF-DAB has the dual functions of CO_(2)capture and conversion, propargylic alcohols were completely converted into α-alkylidene cyclic carbonate or α–hydroxy ketone as high value-added product under atmospheric pressure(CO_(2), 0.1 MPa) and low silver equivalent(0.5 mol%). Notably, Ag@PAF-DAB exhibited broad substrate diversity, high stability,and excellent reusability. By applying FTIR and GC, the key to green synthetic route of α–hydroxy ketone was confirmed to lie in the further hydration of α-alkylidene cyclic carbonate.展开更多
Benzimidazoles are very important chemical materials in the pharmaceutical industry,and the most common synthetic route is cyclization of o-phenylenediamine with carbon sources,in which utilization of inexpensive and ...Benzimidazoles are very important chemical materials in the pharmaceutical industry,and the most common synthetic route is cyclization of o-phenylenediamine with carbon sources,in which utilization of inexpensive and abundant CO_(2)as C1 source is very impressive.Porous aromatic frameworks(PAFs)with highly desired skeletons have attracted great attentions in gas capture and catalysis.Herein,B-based PAF-165 and PAF-166 are designed and synthesized via Friedel-Crafts alkylation reaction,which present high surface areas as well as high stability.Benefiting from the abundant electron-deficient B centers,both PAFs exhibit excellent selective CO_(2)adsorption abilities.The presence of sterically hindered B units in PAFs can act as Lewis acid active sites for the frustrated Lewis pairs(FLPs)in situ formation with ophenylenediamine,thus promoting the synthesis of benzimidazole.The optimal reaction conditions for o-phenylenediamine cyclization with PAF catalysts are explored,and the reaction mechanism is also proposed.This work provides feasible ideas for incorporating FLPs within porous materials as reusable heterogeneous catalysts for CO_(2)capture and conversion.展开更多
In the context of peak carbon and carbon neutrality,the utilization of CO_(2)has attracted attention with the aim of reducing carbon emissions by converting CO_(2)into high-value chemicals or energy.Methanol(MeOH),whi...In the context of peak carbon and carbon neutrality,the utilization of CO_(2)has attracted attention with the aim of reducing carbon emissions by converting CO_(2)into high-value chemicals or energy.Methanol(MeOH),which is both a hydrogen and a carbon carrier,is considered the most promising among the CO_(2)-conversion products.This paper focus on routes for electrochemical conversion of CO_(2)to MeOH using green power and green hydrogen to achieve negative CO_(2)emissions.Three feasible technical routes for electrochemical conversion of CO_(2)to MeOH are proposed in this paper:Route 1,electrolysis of water to H_(2)and hydrogenation of CO_(2)to MeOH;Route 2,electrochemical reduction of CO_(2)to MeOH;and Route 3,co-electrolysis of CO_(2)-H_(2)O to syngas and synthesis of MeOH from syngas.Techno-economic assessments of the three routes are conducted using technical maturity surveys,system simulations and cost analyses to provide reference data for route selection for CO_(2)conversion to MeOH in China.Compared with the other routes,Route 1 is advantageous in terms of technical maturity and commercial application prospects.Although Route 1 is presently economically unviable,it is expected to achieve profitability and commercial application in the future with decreases in the cost of renewable power and continuous development of water-electrolysis technology.展开更多
基金Supported by Capture CO_2 and Storage Technology Jointly Studied by USA and China(2013DFB60140-04)Northwest University Graduate Innovative Talent Training Project(YZZ12036)
文摘CaO-based sorbent is considered to be a promising candidate for capturing CO_2 at high temperature. However,the adsorption capacity of CaO decreases sharply with the increase of the carbonation/calcination cycles. In this study, CaO was derived from calcium acetate(CaAc_2), which was doped with different elements(Mg, Al,Ce, Zr and La) to improve the cyclic stability. The carbonation conversion and cyclic stability of sorbents were tested by thermogravimetric analyzer(TGA). The sorbents were characterized by N_2 isothermal adsorption measurements, scanning electron microscopy(SEM) and X-ray diffraction(XRD). The results showed that the cyclic stabilities of all modified sorbents were improved by doping elements, while the carbonation conversions of sorbents in the 1st cycle were not increased by doping different elements. After 22 cycles, the cyclic stabilities of CaO–Al, CaO–Ce and CaO–La were above 96.2%. After 110 cycles, the cyclic stability of CaO–Al was still as high as 87.1%. Furthermore, the carbonation conversion was closely related to the critical time and specific surface area.
基金supported by the National Natural Science Foundation of China (21875079 and 21672078)
文摘Chemical conversion of carbon dioxide(CO2)to value-added useful chemicals like cyclic carbonates represents one potential solution to climate warming.Here,a kind of porous organic polymer(HAT-TP)with large surface area and excellent carbon dioxide uptake capacity is prepared via a condensation reaction to introduce hexaazatriphenylene(HAT)units into triptycene(TP)-based microporous polymer.HAT-TP can coordinate with zinc ions,and the resulting polymer(Zn/HAT-TP)can be utilized as an efficient recyclable catalyst for chemical conversion of CO2 into cyclic carbonates with epoxides.
基金The authors are grateful to the financial support from Shanghai Science and Technology Committee(No.19160712100)National Natural Science Foundation of China(No.21878076).
文摘Global warming caused by excess carbon dioxide(CO_(2))emission has been a focus of the world.The development of neutral carbon technologies becomes a strategic choice for the sustainable human society.Integrating CO_(2) capture and conversion(iCCC)technology can simultaneously convert the captured CO_(2) from flue gas into value-added chemicals,which saves great energies and expenses incurred in CO_(2) compression and transportation processes of conventional carbon capture,utilization,and storage(CCUS)technology.The present review criti-cally discusses the dual-function materials(DFMs)and the iCCC technology at intermediate temperature for methane production and high temperature for syngas production.The design of reactor and optimization of operation conditions are emphasized from the perspective of industrial applications.The dual-fixed-bed reactors mode by switching the flue gas and reactant gases,and the dual-fluidized-bed reactors mode by the circulation of DFMs particles are comparatively reviewed.We hope this review can stimulate further studies including designing and fabricating feasible DFMs,exploring realistic catalytic process for CO_(2) conversion to high value-added chemicals,developing workable reactor modes and optimizing operation conditions,and establishing industrial demonstration for real applications of iCCC technology in the future.
基金supported by the National Key Research and Development Program of China (No. 2019YFB1504003)。
文摘The conversion of propargylic alcohols and carbon dioxide(CO_(2)) into fine chemicals suffers from issues of harsh reaction conditions and difficult catalyst recovery. To achieve efficient CO_(2)activation at low energy consumption, a silver-anchored porous aromatic framework catalyst Ag@PAF-DAB with high active phase density and CO_(2)adsorption capacity was proposed. Since Ag@PAF-DAB has the dual functions of CO_(2)capture and conversion, propargylic alcohols were completely converted into α-alkylidene cyclic carbonate or α–hydroxy ketone as high value-added product under atmospheric pressure(CO_(2), 0.1 MPa) and low silver equivalent(0.5 mol%). Notably, Ag@PAF-DAB exhibited broad substrate diversity, high stability,and excellent reusability. By applying FTIR and GC, the key to green synthetic route of α–hydroxy ketone was confirmed to lie in the further hydration of α-alkylidene cyclic carbonate.
基金the financial support by the Fundamental Research Funds for the Central Universities(No.2412019FZ008)the National Natural Science Foundation of China(Nos.22131004 and U21A20330)the"111 Project(No.B18012)。
文摘Benzimidazoles are very important chemical materials in the pharmaceutical industry,and the most common synthetic route is cyclization of o-phenylenediamine with carbon sources,in which utilization of inexpensive and abundant CO_(2)as C1 source is very impressive.Porous aromatic frameworks(PAFs)with highly desired skeletons have attracted great attentions in gas capture and catalysis.Herein,B-based PAF-165 and PAF-166 are designed and synthesized via Friedel-Crafts alkylation reaction,which present high surface areas as well as high stability.Benefiting from the abundant electron-deficient B centers,both PAFs exhibit excellent selective CO_(2)adsorption abilities.The presence of sterically hindered B units in PAFs can act as Lewis acid active sites for the frustrated Lewis pairs(FLPs)in situ formation with ophenylenediamine,thus promoting the synthesis of benzimidazole.The optimal reaction conditions for o-phenylenediamine cyclization with PAF catalysts are explored,and the reaction mechanism is also proposed.This work provides feasible ideas for incorporating FLPs within porous materials as reusable heterogeneous catalysts for CO_(2)capture and conversion.
基金supported by National Key R&D Program of China(2017YFB0601900)。
文摘In the context of peak carbon and carbon neutrality,the utilization of CO_(2)has attracted attention with the aim of reducing carbon emissions by converting CO_(2)into high-value chemicals or energy.Methanol(MeOH),which is both a hydrogen and a carbon carrier,is considered the most promising among the CO_(2)-conversion products.This paper focus on routes for electrochemical conversion of CO_(2)to MeOH using green power and green hydrogen to achieve negative CO_(2)emissions.Three feasible technical routes for electrochemical conversion of CO_(2)to MeOH are proposed in this paper:Route 1,electrolysis of water to H_(2)and hydrogenation of CO_(2)to MeOH;Route 2,electrochemical reduction of CO_(2)to MeOH;and Route 3,co-electrolysis of CO_(2)-H_(2)O to syngas and synthesis of MeOH from syngas.Techno-economic assessments of the three routes are conducted using technical maturity surveys,system simulations and cost analyses to provide reference data for route selection for CO_(2)conversion to MeOH in China.Compared with the other routes,Route 1 is advantageous in terms of technical maturity and commercial application prospects.Although Route 1 is presently economically unviable,it is expected to achieve profitability and commercial application in the future with decreases in the cost of renewable power and continuous development of water-electrolysis technology.
