Due to the shortage supply of propylene and the development of shale gas,there is increased interest in on-purpose propane dehydrogenation(PDH)technology for propylene production.Ga-based catalysts have great potentia...Due to the shortage supply of propylene and the development of shale gas,there is increased interest in on-purpose propane dehydrogenation(PDH)technology for propylene production.Ga-based catalysts have great potential in PDH,due to the high activity,low carbon deposit and deactivation.Ga-hydrides formed during PDH reduce the rate,selectivity and yield of propylene.In this contribution,CO_(2)is introduced into PDH as a soft oxidant to eliminate the unfavorable intermediate species Ga^(δ+)-Hx re-generating Ga^(3+)-O pairs,and also minimize coke deposition thereby improving the catalytic performance.In situ diffuse reflectance infrared Fourier transform(DRIFT)spectroscopy experiments show that CO_(2)can effectively eliminate Ga^(δ+)-Hx.At different temperatures,co-feeding CO_(2)during PDH over Ga_(2)O_(3)/SiO_(2)catalysts with different loadings significantly improves the stability of the conversion and selectivity,especially the latter,and provide a new dimension for improving the performance of PDH process.展开更多
CO_(2)-assisted oxidative dehydrogenation of propane(CO_(2)-ODHP)is an attractive strategy to offset the demand gap of propylene due to its potentiality of reducing CO_(2)emissions,especially under the demands of peak...CO_(2)-assisted oxidative dehydrogenation of propane(CO_(2)-ODHP)is an attractive strategy to offset the demand gap of propylene due to its potentiality of reducing CO_(2)emissions,especially under the demands of peaking CO_(2)emissions and carbon neutrality.The introduction of CO_(2)as a soft oxidant into the reaction not only averts the over-oxidation of products,but also maintains the high oxidation state of the redox-active sites.Furthermore,the presence of CO_(2)increases the conversion of propane by coupling the dehydrogenation of propane(DHP)with the reverse water gas reaction(RWGS)and inhibits the coking formation to prolong the lifetime of catalysts via the reverse Boudouard reaction.An effective catalyst should selectively activate the C–H bond but suppress the C–C cleavage.However,to prepare such a catalyst remains challenging.Chromium-based catalysts are always applied in industrial application of DHP;however,their toxic properties are harmful to the environment.In this aspect,exploring environment-friendly and sustainable catalytic systems with Cr-free is an important issue.In this review,we outline the development of the CO_(2)-ODHP especially in the last ten years,including the structural information,catalytic performances,and mechanisms of chromium-free metal-based catalyst systems,and the role of CO_(2)in the reaction.We also present perspectives for future progress in the CO_(2)-ODHP.展开更多
文摘Due to the shortage supply of propylene and the development of shale gas,there is increased interest in on-purpose propane dehydrogenation(PDH)technology for propylene production.Ga-based catalysts have great potential in PDH,due to the high activity,low carbon deposit and deactivation.Ga-hydrides formed during PDH reduce the rate,selectivity and yield of propylene.In this contribution,CO_(2)is introduced into PDH as a soft oxidant to eliminate the unfavorable intermediate species Ga^(δ+)-Hx re-generating Ga^(3+)-O pairs,and also minimize coke deposition thereby improving the catalytic performance.In situ diffuse reflectance infrared Fourier transform(DRIFT)spectroscopy experiments show that CO_(2)can effectively eliminate Ga^(δ+)-Hx.At different temperatures,co-feeding CO_(2)during PDH over Ga_(2)O_(3)/SiO_(2)catalysts with different loadings significantly improves the stability of the conversion and selectivity,especially the latter,and provide a new dimension for improving the performance of PDH process.
基金financially supported by the National Natural Science Foundation of China (Nos. 21978160, 22078182 and 21908139)the Key Industrial Innovation Project of Shaanxi Provincial Science and Technology Department (No. 2019ZDLGY06-04)+1 种基金the Project Supported by Natural Science Basic Research Plan in Shaanxi Province of China (No. 2019JLM-16)the Key Project of Education Department of Shaanxi Province (No. 21JY005)
文摘CO_(2)-assisted oxidative dehydrogenation of propane(CO_(2)-ODHP)is an attractive strategy to offset the demand gap of propylene due to its potentiality of reducing CO_(2)emissions,especially under the demands of peaking CO_(2)emissions and carbon neutrality.The introduction of CO_(2)as a soft oxidant into the reaction not only averts the over-oxidation of products,but also maintains the high oxidation state of the redox-active sites.Furthermore,the presence of CO_(2)increases the conversion of propane by coupling the dehydrogenation of propane(DHP)with the reverse water gas reaction(RWGS)and inhibits the coking formation to prolong the lifetime of catalysts via the reverse Boudouard reaction.An effective catalyst should selectively activate the C–H bond but suppress the C–C cleavage.However,to prepare such a catalyst remains challenging.Chromium-based catalysts are always applied in industrial application of DHP;however,their toxic properties are harmful to the environment.In this aspect,exploring environment-friendly and sustainable catalytic systems with Cr-free is an important issue.In this review,we outline the development of the CO_(2)-ODHP especially in the last ten years,including the structural information,catalytic performances,and mechanisms of chromium-free metal-based catalyst systems,and the role of CO_(2)in the reaction.We also present perspectives for future progress in the CO_(2)-ODHP.
