As a highly reactive reaction intermediate,surface gallium hydride(Ga–H)has garnered significant attention due to its critical role in various catalytic reactions.However,the detailed experimental characterization of...As a highly reactive reaction intermediate,surface gallium hydride(Ga–H)has garnered significant attention due to its critical role in various catalytic reactions.However,the detailed experimental characterization of this unique species remains challenging.Recently,we have demonstrated that solid-state NMR can be an effective tool for studying surface Ga–H.In this work,we report a comparative solid-state NMR study on H_(2) activation over different Ga_(2)O_(3) polymorphs,specificallyα-,β-andγ-Ga_(2)O_(3).^(1)H solid-state NMR enabled the identification of Ga–H species formed on all the three samples following high-temperature H_(2) treatment.The characteristic ^(1)H NMR signals of Ga–H species are resolved using J-coupling-based double-resonance NMR methods,revealing highly similar lineshapes of Ga–H for all the Ga_(2)O_(3) samples.This suggests potentially similar surface Ga–H configurations among different Ga_(2)O_(3) polymorphs.In addition,the local hydrogen environments on the oxide surfaces are further explored using two-dimensional(2D)^(1)H–^(1)H homonuclear correlation spectra,revealing multiple spatially proximate Ga–H and Ga–H/–OH pairs on different Ga_(2)O_(3) polymorphs.These findings provide insights into the potential mechanism of H_(2) dissociation.Overall,this work offers new perspectives on the local structure of surface Ga–H on Ga_(2)O_(3),and the analytical approach presented here can be further extended to the study of other Ga-based catalysts and other metal hydride species.展开更多
Some proteins perform their biological functions by changing their material states through liquid-liquid phase separation.Upon phase separation,the protein condenses into a concentrated liquid phase and sometimes into...Some proteins perform their biological functions by changing their material states through liquid-liquid phase separation.Upon phase separation,the protein condenses into a concentrated liquid phase and sometimes into a gel phase,changing its dynamic properties and intermolecular interactions,thereby regulating cellular functions.Although the biological significance of this phenomenon has been widely recognized by researchers,there is still a lack of a comprehensive understanding of the structural and dynamic properties of the protein in the condensed phase.In this phase,molecules usually contain domains with varied dynamic properties and undergo intermediate exchanges.Magic angle spinning(MAS)solid-state NMR(SSNMR)experiments are very powerful in studying rigid protein polymers such as amyloid.The incorporation of solution-like experiments into SSNMR and the development of J-coupling based MAS SSNMR techniques extend its ability to study partially mobile segments of proteins in a condensed liquid or gel phase which are not visible by solution NMR or dipolar-coupling based SSNMR.Therefore,it has been applied in studying protein condensation and has provided very important information that is hard to obtain by other techniques.展开更多
基金financially supported by the National Key R&D Program of China(No.2021YFA1502803)the National Natural Science Foundation of China(Nos.22325405,22372160,22432005 and 22321002)Dalian Science and Technology Talent Innovation Program(No.2024RG009).
文摘As a highly reactive reaction intermediate,surface gallium hydride(Ga–H)has garnered significant attention due to its critical role in various catalytic reactions.However,the detailed experimental characterization of this unique species remains challenging.Recently,we have demonstrated that solid-state NMR can be an effective tool for studying surface Ga–H.In this work,we report a comparative solid-state NMR study on H_(2) activation over different Ga_(2)O_(3) polymorphs,specificallyα-,β-andγ-Ga_(2)O_(3).^(1)H solid-state NMR enabled the identification of Ga–H species formed on all the three samples following high-temperature H_(2) treatment.The characteristic ^(1)H NMR signals of Ga–H species are resolved using J-coupling-based double-resonance NMR methods,revealing highly similar lineshapes of Ga–H for all the Ga_(2)O_(3) samples.This suggests potentially similar surface Ga–H configurations among different Ga_(2)O_(3) polymorphs.In addition,the local hydrogen environments on the oxide surfaces are further explored using two-dimensional(2D)^(1)H–^(1)H homonuclear correlation spectra,revealing multiple spatially proximate Ga–H and Ga–H/–OH pairs on different Ga_(2)O_(3) polymorphs.These findings provide insights into the potential mechanism of H_(2) dissociation.Overall,this work offers new perspectives on the local structure of surface Ga–H on Ga_(2)O_(3),and the analytical approach presented here can be further extended to the study of other Ga-based catalysts and other metal hydride species.
基金supported by the National Natural Science Foundation of China(No.32171185,No.31770790)the National Key R&D Program of China(No.2017YFA0504804).
文摘Some proteins perform their biological functions by changing their material states through liquid-liquid phase separation.Upon phase separation,the protein condenses into a concentrated liquid phase and sometimes into a gel phase,changing its dynamic properties and intermolecular interactions,thereby regulating cellular functions.Although the biological significance of this phenomenon has been widely recognized by researchers,there is still a lack of a comprehensive understanding of the structural and dynamic properties of the protein in the condensed phase.In this phase,molecules usually contain domains with varied dynamic properties and undergo intermediate exchanges.Magic angle spinning(MAS)solid-state NMR(SSNMR)experiments are very powerful in studying rigid protein polymers such as amyloid.The incorporation of solution-like experiments into SSNMR and the development of J-coupling based MAS SSNMR techniques extend its ability to study partially mobile segments of proteins in a condensed liquid or gel phase which are not visible by solution NMR or dipolar-coupling based SSNMR.Therefore,it has been applied in studying protein condensation and has provided very important information that is hard to obtain by other techniques.
