Organic structure directingagents(OSDAs),suchas tetrapropylammonium(TPA)cations,serve as crucial templates for the formation of zeolite frameworks.These organic molecules interact with inorganic species,guiding the as...Organic structure directingagents(OSDAs),suchas tetrapropylammonium(TPA)cations,serve as crucial templates for the formation of zeolite frameworks.These organic molecules interact with inorganic species,guiding the assembly of the zeolite structure.In this study,we inves-tigate the complex interplay between boron species and TPA cations during the crystallization of[B,Al]-ZSM-5 zeolites.Two-dimensional(2D)11B-{1H}cross-polarization heteronuclear correlation(CP-HECTOR)NMRexperiments elucidate distinct interactions between two boron species,B(IV)-1 and B(IV)-2,and the propyl chain of the TPAs.Amorphous B(IV)-1 species exhibit a strong preference for proximity to the nitrogen cation center of the OSDAs,while framework B(IV)-2 species engage with components situated at greater distances from the cation center.Moreover,13C-{11B}symmetry-based resonance-echo saturation-pulse double-resonance(S-RESPDOR)experiments revealed that framework boron species preferentially occupy the straight channels of the MFI structure,as evidenced by their interaction with specificmethyl groups on the TPAmolecules.This observation provides valuable insights into the crystallization mechanism of boron-based zeolites,suggesting that the conformation and orientation of the OSDA molecules play a critical role in determining the location of boron atoms within the zeolite framework.展开更多
The size and shape of rice grains influence their yield and commercial value.We investigated the role of OsDA1,a rice homolog of the Arabidopsis DA1 gene,in regulating grain size and shape.OsDA1 was highly expressed i...The size and shape of rice grains influence their yield and commercial value.We investigated the role of OsDA1,a rice homolog of the Arabidopsis DA1 gene,in regulating grain size and shape.OsDA1 was highly expressed in young spikelets and glumes.Its overexpression led to enlarged seeds with increased width and decreased length/width ratio(LWR)and knocking out OsDA1 reduced grain width and increased grain length and LWR.A R310K point mutation in the DA1-like domain is a potential target for breeding for increased grain width and length.OsDA1 interacted with TCP gene-family proteins to regulate grain size and shape.Our findings deepen our understanding of the molecular mechanisms underlying grain size regulation and provide useful information for improving grain yield.展开更多
To reduce greenhouse gas emission from oil and gas production,it is essential to better convert methane to useful chemicals(rather) than to flare it.Conversion of methane to liquid oxygenates(mainly methanol) has attr...To reduce greenhouse gas emission from oil and gas production,it is essential to better convert methane to useful chemicals(rather) than to flare it.Conversion of methane to liquid oxygenates(mainly methanol) has attracted extensive attention and countless efforts have been made;however,running this reaction in a green,efficient,and practical way has remained elusive.The novel catalyst and oxidants play a critical role in activating methane and converting it to oxygenates(methanol).In this review,the work of commonly used oxidants for methane partial oxidation have been summarized,in which,earth abundant oxidants,O;and H;O are promising.Moreover,H;or CO can activate O;to produce H;O;that catalyzes methane partial oxidation more efficiently and selectively than O;or H;O.Therefore,the work of using reducing agent,such as CO and H;have been reviewed,focusing on rational catalyst design that features multifunction(H;O;production and CH;activation).The novel catalyst design has advanced this reaction towards practicality with green oxidants and H;using zeolites-based catalyst.Environmentally friendly zeolite preparation methods and novel two-dimensional(2 D) zeolites that can reduce waste,improve synthesis and catalytical performance substantially are also reviewed in this work to provide insights for a more comprehensive approach to meet the environment protection needs.展开更多
基金supported by the National Energy R&D Center of Petroleum Refining Technology(RIPP,SINOPEC),the National Natural Science Foundation of China(Grants 22161132028,22172177,22225205,22372191 and 22372178)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0540000)+2 种基金the International Partnership Program of the Chinese Academy of Sciences(314GJH2022022FN)Natural Science Foundation of Hubei Province(2021CFA021)Hubei International Scientific and Technological Cooperation Program(2024EHA043)and Base(SH2303).
文摘Organic structure directingagents(OSDAs),suchas tetrapropylammonium(TPA)cations,serve as crucial templates for the formation of zeolite frameworks.These organic molecules interact with inorganic species,guiding the assembly of the zeolite structure.In this study,we inves-tigate the complex interplay between boron species and TPA cations during the crystallization of[B,Al]-ZSM-5 zeolites.Two-dimensional(2D)11B-{1H}cross-polarization heteronuclear correlation(CP-HECTOR)NMRexperiments elucidate distinct interactions between two boron species,B(IV)-1 and B(IV)-2,and the propyl chain of the TPAs.Amorphous B(IV)-1 species exhibit a strong preference for proximity to the nitrogen cation center of the OSDAs,while framework B(IV)-2 species engage with components situated at greater distances from the cation center.Moreover,13C-{11B}symmetry-based resonance-echo saturation-pulse double-resonance(S-RESPDOR)experiments revealed that framework boron species preferentially occupy the straight channels of the MFI structure,as evidenced by their interaction with specificmethyl groups on the TPAmolecules.This observation provides valuable insights into the crystallization mechanism of boron-based zeolites,suggesting that the conformation and orientation of the OSDA molecules play a critical role in determining the location of boron atoms within the zeolite framework.
基金This work is supported in part by the National Transgenic Science and Technology Program(2016ZX08010-002)National Natural Science Foundation of China(157101834)Agricultural Science and Technology Innovation Program of CAAS.
文摘The size and shape of rice grains influence their yield and commercial value.We investigated the role of OsDA1,a rice homolog of the Arabidopsis DA1 gene,in regulating grain size and shape.OsDA1 was highly expressed in young spikelets and glumes.Its overexpression led to enlarged seeds with increased width and decreased length/width ratio(LWR)and knocking out OsDA1 reduced grain width and increased grain length and LWR.A R310K point mutation in the DA1-like domain is a potential target for breeding for increased grain width and length.OsDA1 interacted with TCP gene-family proteins to regulate grain size and shape.Our findings deepen our understanding of the molecular mechanisms underlying grain size regulation and provide useful information for improving grain yield.
文摘To reduce greenhouse gas emission from oil and gas production,it is essential to better convert methane to useful chemicals(rather) than to flare it.Conversion of methane to liquid oxygenates(mainly methanol) has attracted extensive attention and countless efforts have been made;however,running this reaction in a green,efficient,and practical way has remained elusive.The novel catalyst and oxidants play a critical role in activating methane and converting it to oxygenates(methanol).In this review,the work of commonly used oxidants for methane partial oxidation have been summarized,in which,earth abundant oxidants,O;and H;O are promising.Moreover,H;or CO can activate O;to produce H;O;that catalyzes methane partial oxidation more efficiently and selectively than O;or H;O.Therefore,the work of using reducing agent,such as CO and H;have been reviewed,focusing on rational catalyst design that features multifunction(H;O;production and CH;activation).The novel catalyst design has advanced this reaction towards practicality with green oxidants and H;using zeolites-based catalyst.Environmentally friendly zeolite preparation methods and novel two-dimensional(2 D) zeolites that can reduce waste,improve synthesis and catalytical performance substantially are also reviewed in this work to provide insights for a more comprehensive approach to meet the environment protection needs.
