Solid oxide electrolysis cells(SOECs)can convert electricity to chemicals with high efficiency at ~600-900℃,and have attracted widespread attention in renewable energy conversion and storage.SOECs operate in the inve...Solid oxide electrolysis cells(SOECs)can convert electricity to chemicals with high efficiency at ~600-900℃,and have attracted widespread attention in renewable energy conversion and storage.SOECs operate in the inverse mode of solid oxide fuel cells(SOFCs)and therefore inherit most of the advantages of SOFC materials and energy conversion processes.However,the external bias that drives the electrochemical process will strongly change the chemical environments in both in the cathode and anode,therefore necessitating careful reconsideration of key materials and electrocatalysis processes.More importantly,SOECs provide a unique advantage of electrothermal catalysis,especially in converting stable low-carbon alkanes such as methane to ethylene with high selectivity.Here,we review the state-of-the-art of SOEC research progress in electrothermal catalysis and key materials and provide a future perspective.展开更多
Introducing and stabilizing oxygen vacancies in oxide catalysts is considered to be a promising strategy for improving catalytic activity and durability.Herein,we quantitatively create oxygen vacancies in the lattice ...Introducing and stabilizing oxygen vacancies in oxide catalysts is considered to be a promising strategy for improving catalytic activity and durability.Herein,we quantitatively create oxygen vacancies in the lattice of porous single-crystallineβ-Ga_(2)O_(3)monoliths by reduction treatments and stabilize them through the long-range ordering of crystal lattice to enhance catalytic activity and durability.The combination analysis of time-of-flight neutron powder diffraction and extended x-ray absorption fine structure discloses that the preferential generation of oxygen vacancy tends to occur at the site of tetrahedral coordination oxygen ions(O_(Ⅲ)sites),which contributes to the formation of unsaturated Ga-O coordination in the monoclinic phase.The oxygen vacancies are randomly distributed in lattice even though some of them are present in the form of domain defect in the PSC Ga_(2)O_(3)monoliths after the reduction treatment.The number of oxygen vacancies in the reduced monoliths gives 2.32×10^(13),2.87×10^(13),and 3.45×10^(13)mg^(-1)for the Ga_(2)O_(2.952),Ga_(2)O_(2.895),and Ga_(2)O_(2.880),respectively.We therefore demonstrate the exceptionally high C_(2)H_(4)selectivity of~100%at the C_(2)H_(6)conversion of~37%for nonoxidative dehydrogenation of C_(2)H_(6)to C_(2)H_(4).We further demonstrate the excellent durability even at 620℃for 240 h of continuous operation.展开更多
基金the National Key Research and Development Program of China(2017YFA0700102)Natural Science Foundation of China(91845202)+3 种基金Dalian National Laboratory for Clean Energy(DNL180404)Strategic Priority Research Program of Chinese Academy of Sciences(XDB2000000)Natural Science Foundation of Fujian Province(2018J01088)State Key Laboratory of Structural Chemistry(20170011,20200012)。
文摘Solid oxide electrolysis cells(SOECs)can convert electricity to chemicals with high efficiency at ~600-900℃,and have attracted widespread attention in renewable energy conversion and storage.SOECs operate in the inverse mode of solid oxide fuel cells(SOFCs)and therefore inherit most of the advantages of SOFC materials and energy conversion processes.However,the external bias that drives the electrochemical process will strongly change the chemical environments in both in the cathode and anode,therefore necessitating careful reconsideration of key materials and electrocatalysis processes.More importantly,SOECs provide a unique advantage of electrothermal catalysis,especially in converting stable low-carbon alkanes such as methane to ethylene with high selectivity.Here,we review the state-of-the-art of SOEC research progress in electrothermal catalysis and key materials and provide a future perspective.
基金the Natural Science Foundation of China(22325506,22379147,22002167,22101282,and 22279142)the Youth Innovation Promotion of Chinese Academy of Sciences(2023318)the Natural Science Foundation of Fujian Province(2020J05082 and 2020J01113).
文摘Introducing and stabilizing oxygen vacancies in oxide catalysts is considered to be a promising strategy for improving catalytic activity and durability.Herein,we quantitatively create oxygen vacancies in the lattice of porous single-crystallineβ-Ga_(2)O_(3)monoliths by reduction treatments and stabilize them through the long-range ordering of crystal lattice to enhance catalytic activity and durability.The combination analysis of time-of-flight neutron powder diffraction and extended x-ray absorption fine structure discloses that the preferential generation of oxygen vacancy tends to occur at the site of tetrahedral coordination oxygen ions(O_(Ⅲ)sites),which contributes to the formation of unsaturated Ga-O coordination in the monoclinic phase.The oxygen vacancies are randomly distributed in lattice even though some of them are present in the form of domain defect in the PSC Ga_(2)O_(3)monoliths after the reduction treatment.The number of oxygen vacancies in the reduced monoliths gives 2.32×10^(13),2.87×10^(13),and 3.45×10^(13)mg^(-1)for the Ga_(2)O_(2.952),Ga_(2)O_(2.895),and Ga_(2)O_(2.880),respectively.We therefore demonstrate the exceptionally high C_(2)H_(4)selectivity of~100%at the C_(2)H_(6)conversion of~37%for nonoxidative dehydrogenation of C_(2)H_(6)to C_(2)H_(4).We further demonstrate the excellent durability even at 620℃for 240 h of continuous operation.
