通过探究催化转移氢化(catalytic transfer hydrogenation,CTH)使高含氧量生物质加氢脱氧为高值平台分子的新策略,以实现生物质的资源化与利用和达成生产净零碳排放燃料的目标。文中以Zr/Hf金属氧化物非均相催化体系设计、构筑及性能调...通过探究催化转移氢化(catalytic transfer hydrogenation,CTH)使高含氧量生物质加氢脱氧为高值平台分子的新策略,以实现生物质的资源化与利用和达成生产净零碳排放燃料的目标。文中以Zr/Hf金属氧化物非均相催化体系设计、构筑及性能调控为基本思路,以乙酰丙酸、糠醛、5-羟甲基糠醛及γ-戊内酯等重要生物质平台分子的可控定向转化为主线,重点评估了催化剂结构对应的酸碱活性位点在Meerwein-Ponndorf-Verley(MPV)反应中的关键作用,探讨并展望了Zr/Hf酸碱双功能催化剂在生物质平台分子转化为高值化学品领域的发展前景。本研究不仅对催化剂活性位点(Lewis/Br?nsted酸和碱)在相应生物质转化过程中的反应机理做出了归纳和总结,并且提出了兼顾经济效益和环境影响的新型固体酸催化剂的设计思路和策略。展开更多
采用相图计算(CALPHAD:Calculation of phase diagrams)方法对Zr-X(X=Li,Na,K,Sc,Hf)5个二元体系进行了相图热力学研究.基于实验数据,通过热力学优化计算获得了一套描述液相及(αZr),(βZr),(Li),(Na),(K),(αSc),(βSc),(αHf)和(βHf...采用相图计算(CALPHAD:Calculation of phase diagrams)方法对Zr-X(X=Li,Na,K,Sc,Hf)5个二元体系进行了相图热力学研究.基于实验数据,通过热力学优化计算获得了一套描述液相及(αZr),(βZr),(Li),(Na),(K),(αSc),(βSc),(αHf)和(βHf)相的热力学参数.Zr-Li,Zr-Na和Zr-K体系中的气相视为理想气体.与实验相图数据对比发现,本文获得的热力学参数能够准确地描述实验相平衡数据.展开更多
The electronic structures of pure Ti, Zr and Hf metals with hcp structure were determined by one atom (OA) theory. According to the electronic structures of these metals,their potential curves, cohesive energies, latt...The electronic structures of pure Ti, Zr and Hf metals with hcp structure were determined by one atom (OA) theory. According to the electronic structures of these metals,their potential curves, cohesive energies, lattice constants, elasticities and the temperature dependence of linear thermal expansion coefficients were calculated. The electronic structures and characteristic properties of these metals with bcc and fcc structures and liquids were also studied. The results show that the electronic structures of Ti, Zr and Hf metals are respectively [Ar](3d n) 0.481 0 (3d c) 2.085 7 (4s c) 1.000 0 (4s f) 0.433 3 , [Kr](4d n) 0.396 8 (4d c) 2.142 8 (5s c) 1.262 0 (5s f) 0.198 4 , [Xe](5d n) 0.368 0 (5d c) 2.041 4 (6s c) 1.406 6 (6s f) 0.184 0 . It is explained why the pure Ti, Zr and Hf metals with hcp and bcc structures can exist naturally, while those with fcc structure can not.展开更多
文摘通过探究催化转移氢化(catalytic transfer hydrogenation,CTH)使高含氧量生物质加氢脱氧为高值平台分子的新策略,以实现生物质的资源化与利用和达成生产净零碳排放燃料的目标。文中以Zr/Hf金属氧化物非均相催化体系设计、构筑及性能调控为基本思路,以乙酰丙酸、糠醛、5-羟甲基糠醛及γ-戊内酯等重要生物质平台分子的可控定向转化为主线,重点评估了催化剂结构对应的酸碱活性位点在Meerwein-Ponndorf-Verley(MPV)反应中的关键作用,探讨并展望了Zr/Hf酸碱双功能催化剂在生物质平台分子转化为高值化学品领域的发展前景。本研究不仅对催化剂活性位点(Lewis/Br?nsted酸和碱)在相应生物质转化过程中的反应机理做出了归纳和总结,并且提出了兼顾经济效益和环境影响的新型固体酸催化剂的设计思路和策略。
文摘采用相图计算(CALPHAD:Calculation of phase diagrams)方法对Zr-X(X=Li,Na,K,Sc,Hf)5个二元体系进行了相图热力学研究.基于实验数据,通过热力学优化计算获得了一套描述液相及(αZr),(βZr),(Li),(Na),(K),(αSc),(βSc),(αHf)和(βHf)相的热力学参数.Zr-Li,Zr-Na和Zr-K体系中的气相视为理想气体.与实验相图数据对比发现,本文获得的热力学参数能够准确地描述实验相平衡数据.
基金TheNaturalScienceFoundationofHunanProvince (No .99JZY10 0 5 )
文摘The electronic structures of pure Ti, Zr and Hf metals with hcp structure were determined by one atom (OA) theory. According to the electronic structures of these metals,their potential curves, cohesive energies, lattice constants, elasticities and the temperature dependence of linear thermal expansion coefficients were calculated. The electronic structures and characteristic properties of these metals with bcc and fcc structures and liquids were also studied. The results show that the electronic structures of Ti, Zr and Hf metals are respectively [Ar](3d n) 0.481 0 (3d c) 2.085 7 (4s c) 1.000 0 (4s f) 0.433 3 , [Kr](4d n) 0.396 8 (4d c) 2.142 8 (5s c) 1.262 0 (5s f) 0.198 4 , [Xe](5d n) 0.368 0 (5d c) 2.041 4 (6s c) 1.406 6 (6s f) 0.184 0 . It is explained why the pure Ti, Zr and Hf metals with hcp and bcc structures can exist naturally, while those with fcc structure can not.
