(C_(6)H_(14)N_(2))[Na(ClO_(4))_(3)]是新型含能钙钛矿化合物的典型代表,需明确其热分解行为、热分解机制及感度特性,以推动其在配方中的应用。以差示扫描量热-热重分析方法实现了分解放热量、分解温度等参数的获取;以动力学模拟计算...(C_(6)H_(14)N_(2))[Na(ClO_(4))_(3)]是新型含能钙钛矿化合物的典型代表,需明确其热分解行为、热分解机制及感度特性,以推动其在配方中的应用。以差示扫描量热-热重分析方法实现了分解放热量、分解温度等参数的获取;以动力学模拟计算解析了相关分解机理;以同步热分析-红外-质谱联用技术结合原位红外技术探索了(C_(6)H_(14)N_(2))[Na(ClO_(4))_(3)]的分解产物及分解历程;以国军标法获得了热感度、摩擦感度与撞击感度参数。结果表明:在10℃·min^(-1)的升温速率下,(C_(6)H_(14)N_(2))[Na(ClO_(4))_(3)]分解放热量为4227 J·g^(-1),分解温度则达到345℃,高于黑索今(RDX)、奥克托今(HMX)、六硝基六氮杂异伍兹烷(CL-20)等多数现役含能材料,显示了优异的热稳定性;分解产物研究表明其立方笼状骨架有效稳定了内部结合的有机物分子,使其热稳定性较高。此外,(C_(6)H_(14)N_(2))[Na(ClO_(4))_(3)]在100℃下加热48 h的放气量约0.04 m L·g^(-1),撞击感度与机械感度分别为32%和80%,优于RDX和HMX。展开更多
Solar-driven CO_(2)conversion to prepare value-added products is highly desirable but challenging.Central to the achievement of multi-carbon products via CO_(2)photoconversion is to break the bottlenecks of C-C coupli...Solar-driven CO_(2)conversion to prepare value-added products is highly desirable but challenging.Central to the achievement of multi-carbon products via CO_(2)photoconversion is to break the bottlenecks of C-C coupling and multi-electron transfer.Herein,a charge relay system consisting of Pd-decorated BiOCl-wrapped CuBi_(2)O_(4)is reported by taking advantage of the synergy of Pd nanoparticles(PdNPs)and heterojunction for efficient CO_(2)-to-C_(2)H_(6)photoconversion.The C_(2)H_(6)production rate reached 167.1µmol g^(-1)h^(-1)with the electron selectivity of 81.1%in the absence of any sacrificial agents.The spectroscopic characterizations indicated that BiOCl nanosheets,acting as the charge relay,directionally transferred the photogenerated electrons from itself and CuBi2O4 nanorods to PdNPs for C-C coupling.The coordinated ensemble of PdNPs and heterojunction significantly elevated the charge separation and transfer efficiency.Moreover,the in-situ spectroscopic analysis supported by theoretical simulations demonstrated that the electron-rich PdNPs generated by the charge relay of PdNPs and heterojunction optimized the CO_(2)-to-C_(2)H_(6)reaction pathway and reduced the energy barrier of the key*CHOCO intermediates.This work develops an innovative strategy to design the multifunctional catalysts for the photoconversion of CO_(2)to value-added carbon products.展开更多
Simultaneous ethane and acetylene removal from a C_(2)-gases mixture(C_(2)H_(6),C_(2)H_(4),and C_(2)H_(2))through a one-step separation process for ethylene purification is of great importance yet challenging in petro...Simultaneous ethane and acetylene removal from a C_(2)-gases mixture(C_(2)H_(6),C_(2)H_(4),and C_(2)H_(2))through a one-step separation process for ethylene purification is of great importance yet challenging in petrochemical industry,owing to their similar molecule sizes and physical properties.Herein,a series of multifunctionalized metal–organic frameworks(MOFs),LIFM-XYY-1∼8(LIFM stands for Lehn Institute of Functional Materials,and XYY are the initials of the first author),are constructed via a dynamic spacer installation(DSI)approach to optimize the pore-nanospaces for efficient C_(2)H_(4) isolation from the ternary C_(2)-gases mixture.Installation of variable organic-spacers into the prototypical MOFs,LIFM-28 or PCN-700,results in dramatically improved pore volume/surface area,contracted pore size,and functionalized pore surface,which in turn bring out high C_(2)-gases uptake capacities,enhanced C_(2)H_(6) and C_(2)H_(2) adsorption selectivities over C_(2)H_(4),and fast adsorption kinetics,providing an effective strategy to achieve delicate trade-off among these indexes for adequate separation performance.Specifically,optimized LIFM-XYY-7 presents four-times C_(2)H_(6) and C_(2)H_(2) adsorption capacities than proto-PCN-700.Dynamic breakthrough experiments reveal that poly-grade C_(2)H_(4)(>99.9%)can be obtained from binary or ternary C_(2)-hydrocarbon mixtures through a single separation process.Combined with themolecular simulations,this work demonstrates a promising protocol of porenanospace engineering via multi-functional optimization by the DSI approach to screen out MOFs for a formidable task.展开更多
The mechanism of the reaction of Ni^+ (~2D) with ethane in the gas-phase wasstudied by using density functional theory. Both the B3LYP and BLYP functionals with standardall-electron basis sets are used to give the det...The mechanism of the reaction of Ni^+ (~2D) with ethane in the gas-phase wasstudied by using density functional theory. Both the B3LYP and BLYP functionals with standardall-electron basis sets are used to give the detailed information of the potential energy surface(PES) of [Ni, C_2, H_6]^+. The mechanisms forming the products CH_4 and H_2 in the reaction of Ni^+with ethane are proposed. The reductive eliminations of CH_4 and H_2 are typicaladdition-elimination reactions. Each of the two reactions consists of two elementary steps; C―C orC―H bond activations to form inserted species followed by isomerizations to form product-likeintermediate. The rate determining steps for the elimination reactions of forming CH_4 and H_2 arethe isomerizations of the inserted species rather than C―C or C―H bond activations. Theelimination reaction of forming H_2 was found to be thermodynamically favored compared to that ofCH_4.展开更多
文摘(C_(6)H_(14)N_(2))[Na(ClO_(4))_(3)]是新型含能钙钛矿化合物的典型代表,需明确其热分解行为、热分解机制及感度特性,以推动其在配方中的应用。以差示扫描量热-热重分析方法实现了分解放热量、分解温度等参数的获取;以动力学模拟计算解析了相关分解机理;以同步热分析-红外-质谱联用技术结合原位红外技术探索了(C_(6)H_(14)N_(2))[Na(ClO_(4))_(3)]的分解产物及分解历程;以国军标法获得了热感度、摩擦感度与撞击感度参数。结果表明:在10℃·min^(-1)的升温速率下,(C_(6)H_(14)N_(2))[Na(ClO_(4))_(3)]分解放热量为4227 J·g^(-1),分解温度则达到345℃,高于黑索今(RDX)、奥克托今(HMX)、六硝基六氮杂异伍兹烷(CL-20)等多数现役含能材料,显示了优异的热稳定性;分解产物研究表明其立方笼状骨架有效稳定了内部结合的有机物分子,使其热稳定性较高。此外,(C_(6)H_(14)N_(2))[Na(ClO_(4))_(3)]在100℃下加热48 h的放气量约0.04 m L·g^(-1),撞击感度与机械感度分别为32%和80%,优于RDX和HMX。
基金supported by the National Natural Science Foundation of China(22302002,22375006)the University Science Research Project of Anhui Province(2022AH050182,2022AH020020)。
文摘Solar-driven CO_(2)conversion to prepare value-added products is highly desirable but challenging.Central to the achievement of multi-carbon products via CO_(2)photoconversion is to break the bottlenecks of C-C coupling and multi-electron transfer.Herein,a charge relay system consisting of Pd-decorated BiOCl-wrapped CuBi_(2)O_(4)is reported by taking advantage of the synergy of Pd nanoparticles(PdNPs)and heterojunction for efficient CO_(2)-to-C_(2)H_(6)photoconversion.The C_(2)H_(6)production rate reached 167.1µmol g^(-1)h^(-1)with the electron selectivity of 81.1%in the absence of any sacrificial agents.The spectroscopic characterizations indicated that BiOCl nanosheets,acting as the charge relay,directionally transferred the photogenerated electrons from itself and CuBi2O4 nanorods to PdNPs for C-C coupling.The coordinated ensemble of PdNPs and heterojunction significantly elevated the charge separation and transfer efficiency.Moreover,the in-situ spectroscopic analysis supported by theoretical simulations demonstrated that the electron-rich PdNPs generated by the charge relay of PdNPs and heterojunction optimized the CO_(2)-to-C_(2)H_(6)reaction pathway and reduced the energy barrier of the key*CHOCO intermediates.This work develops an innovative strategy to design the multifunctional catalysts for the photoconversion of CO_(2)to value-added carbon products.
基金supported by the NKRD Program of China(grant no.2021YFA1500401)NSFC Projects(grant nos.21890380,21821003,22001271,22090061,and 21801252)+1 种基金the LIRT Project of Guangdong PRTP(grant no.2017BT01C161)FRF for the Central Universities(grant no.20lgpy79).
文摘Simultaneous ethane and acetylene removal from a C_(2)-gases mixture(C_(2)H_(6),C_(2)H_(4),and C_(2)H_(2))through a one-step separation process for ethylene purification is of great importance yet challenging in petrochemical industry,owing to their similar molecule sizes and physical properties.Herein,a series of multifunctionalized metal–organic frameworks(MOFs),LIFM-XYY-1∼8(LIFM stands for Lehn Institute of Functional Materials,and XYY are the initials of the first author),are constructed via a dynamic spacer installation(DSI)approach to optimize the pore-nanospaces for efficient C_(2)H_(4) isolation from the ternary C_(2)-gases mixture.Installation of variable organic-spacers into the prototypical MOFs,LIFM-28 or PCN-700,results in dramatically improved pore volume/surface area,contracted pore size,and functionalized pore surface,which in turn bring out high C_(2)-gases uptake capacities,enhanced C_(2)H_(6) and C_(2)H_(2) adsorption selectivities over C_(2)H_(4),and fast adsorption kinetics,providing an effective strategy to achieve delicate trade-off among these indexes for adequate separation performance.Specifically,optimized LIFM-XYY-7 presents four-times C_(2)H_(6) and C_(2)H_(2) adsorption capacities than proto-PCN-700.Dynamic breakthrough experiments reveal that poly-grade C_(2)H_(4)(>99.9%)can be obtained from binary or ternary C_(2)-hydrocarbon mixtures through a single separation process.Combined with themolecular simulations,this work demonstrates a promising protocol of porenanospace engineering via multi-functional optimization by the DSI approach to screen out MOFs for a formidable task.
文摘The mechanism of the reaction of Ni^+ (~2D) with ethane in the gas-phase wasstudied by using density functional theory. Both the B3LYP and BLYP functionals with standardall-electron basis sets are used to give the detailed information of the potential energy surface(PES) of [Ni, C_2, H_6]^+. The mechanisms forming the products CH_4 and H_2 in the reaction of Ni^+with ethane are proposed. The reductive eliminations of CH_4 and H_2 are typicaladdition-elimination reactions. Each of the two reactions consists of two elementary steps; C―C orC―H bond activations to form inserted species followed by isomerizations to form product-likeintermediate. The rate determining steps for the elimination reactions of forming CH_4 and H_2 arethe isomerizations of the inserted species rather than C―C or C―H bond activations. Theelimination reaction of forming H_2 was found to be thermodynamically favored compared to that ofCH_4.
