Pd catalysts suffered from poor selectivity and stability for liquid-phase hydrogenation of maleic anhydride（MA） to gamma-butyrolactone（GBL）.Thus,Pd/C catalysts modified with different Sn loadings were synthesized...Pd catalysts suffered from poor selectivity and stability for liquid-phase hydrogenation of maleic anhydride（MA） to gamma-butyrolactone（GBL）.Thus,Pd/C catalysts modified with different Sn loadings were synthesized,and characterized by XRD,XPS,TEM and elemental mapping.The types of alloy phase and the amounts of the surface Pd-SnOx sites altered along with Sn/Pd mass ratios from 0-1.0synthesized in the process of preparation.The maximum reaction rate was 0.57 mol-GBL/（mol-Pd min）and selectivity was 95.94%when the Sn/Pd mass ratio was 0.6.It might be attributed to the formation of Pd2Sn alloy and less amounts of Pd-SnOx sites.展开更多
对贵金属Pd-X(X=Ag,Ni,Sn)体系的相图热力学文献数据进行严格评估的基础上,采用替代溶液模型描述该3个二元系中液相和FCC_A1相的吉布斯自由能,分别采用亚点阵模型(Pd,Sn)_(1)Sn_(2)、(Pd)_(0.25)(Pd,Sn)_(0.75)和(Pd)_(0.2)(Pd,Sn)_(0.8...对贵金属Pd-X(X=Ag,Ni,Sn)体系的相图热力学文献数据进行严格评估的基础上,采用替代溶液模型描述该3个二元系中液相和FCC_A1相的吉布斯自由能,分别采用亚点阵模型(Pd,Sn)_(1)Sn_(2)、(Pd)_(0.25)(Pd,Sn)_(0.75)和(Pd)_(0.2)(Pd,Sn)_(0.8)描述PdSn_(2)、PdSn_(3)和PdSn_(4)相,通过CALPHAD(calculation of phasediagram)方法获得描述贵金属Pd-X(X=Ag,Ni,Sn)体系的热力学参数。相较于文献报道,本研究得到的热力学参数能更合理地描述Pd-X(X=Ag,Ni,Sn)体系的实验相图数据和热力学数据,尤其在Pd-Ag相图、Pd-Ag体系和Pd-Ni体系FCC_A1的混合焓及Pd-Sn相图富Sn端零变量反应的描述方面。计算结果与实验数据的比较表明本工作获得的热力学参数的准确性。展开更多
Enthalpy for mixing of Cu La and Pd Sn binary systems were predicted by Miedema model. The agreement between the predicting results and the experimental data shows that such model is suitable for not only ferrous me...Enthalpy for mixing of Cu La and Pd Sn binary systems were predicted by Miedema model. The agreement between the predicting results and the experimental data shows that such model is suitable for not only ferrous metal systems, but also rare earth elements and nonferrous metals.展开更多
基金supported by the National Natural Science Foundation,China(Nos.21506138,21606199,21575097 and21375092)the Natural Science Foundation of Zhejiang Province,China(No.LQ15B060001)the China Postdoctoral Science Foundation(No.2016M592015)
文摘Pd catalysts suffered from poor selectivity and stability for liquid-phase hydrogenation of maleic anhydride（MA） to gamma-butyrolactone（GBL）.Thus,Pd/C catalysts modified with different Sn loadings were synthesized,and characterized by XRD,XPS,TEM and elemental mapping.The types of alloy phase and the amounts of the surface Pd-SnOx sites altered along with Sn/Pd mass ratios from 0-1.0synthesized in the process of preparation.The maximum reaction rate was 0.57 mol-GBL/（mol-Pd min）and selectivity was 95.94%when the Sn/Pd mass ratio was 0.6.It might be attributed to the formation of Pd2Sn alloy and less amounts of Pd-SnOx sites.
文摘对贵金属Pd-X(X=Ag,Ni,Sn)体系的相图热力学文献数据进行严格评估的基础上,采用替代溶液模型描述该3个二元系中液相和FCC_A1相的吉布斯自由能,分别采用亚点阵模型(Pd,Sn)_(1)Sn_(2)、(Pd)_(0.25)(Pd,Sn)_(0.75)和(Pd)_(0.2)(Pd,Sn)_(0.8)描述PdSn_(2)、PdSn_(3)和PdSn_(4)相,通过CALPHAD(calculation of phasediagram)方法获得描述贵金属Pd-X(X=Ag,Ni,Sn)体系的热力学参数。相较于文献报道,本研究得到的热力学参数能更合理地描述Pd-X(X=Ag,Ni,Sn)体系的实验相图数据和热力学数据,尤其在Pd-Ag相图、Pd-Ag体系和Pd-Ni体系FCC_A1的混合焓及Pd-Sn相图富Sn端零变量反应的描述方面。计算结果与实验数据的比较表明本工作获得的热力学参数的准确性。
文摘Enthalpy for mixing of Cu La and Pd Sn binary systems were predicted by Miedema model. The agreement between the predicting results and the experimental data shows that such model is suitable for not only ferrous metal systems, but also rare earth elements and nonferrous metals.
