PtnCum(n+m=4) 对甲醇第一步脱氢催化性能的理论研究

佟永纯; 王永成; 王清云

Pt_nCu_m(n+m=4) 对甲醇第一步脱氢催化性能的理论研究

佟永纯^{1, 2},
王永成^1, ,,
王清云²

1.
西北师范大学化学化工学院, 甘肃兰州 730070
2.
河西学院化学化工学院甘肃省河西走廊特色资源利用重点实验室, 甘肃张掖 734000

基金项目:

国家自然科学基金 21263023

甘肃省自然科学基金 1606RJYG220

甘肃省河西走廊特色资源利用重点实验室面上项目 XZ1606

详细信息

通讯作者:
王永成, Tel: 0931-7970237, E-mail: 598552577@qq.com, ycwang@163.com

中图分类号: O641
计量
- 文章访问数: 65
- HTML全文浏览量: 41
- PDF下载量: 9
- 被引次数: 0
出版历程
- 收稿日期: 2016-12-26
- 修回日期: 2017-04-04
- 网络出版日期: 2021-01-23
- 刊出日期: 2017-05-10

Theoretical study on the catalysis activity of Pt_nCu_m(n+m=4) for the first dehydrogenation of methanol

1.
College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, China
2.
College of Chemistry and Chemical Engineering, Key Laboratory of Hexi Corridor Resources Utilization of Gansu, Hexi University, Zhangye 734000, China

Funds:

the National Natural Science Foundation of China 21263023

Natural Science Foundation of Gansu Province 1606RJYG220

General Program of Key Laboratory of Hexi Corridor Resources Utilization of Gansu XZ1606

摘要

摘要: 采用密度泛函理论（DFT）中的B3PW91/LANL2DZ（ECP）方法在Gaussian09程序包中计算了二元合金催化剂Pt_nCu_m（n+m=4）催化甲醇第一步脱氢反应的相关几何参数，主要研究了Pt_nCu_m（n+m=4）在甲醇分子表面的吸附和脱氢反应的机理。通过比较E_ads和脱氢能垒等发现，Pt_nCu_m（n+m=4）催化甲醇脱氢的最优反应路径为甲醇分子中的甲基氢吸附在该二元金属催化剂Pt位点上导致的C-H断裂。并对比了Pt_nCu_m（n+m=4）中Pt与Cu比例对甲醇催化脱氢活性的影响，结果表明，当二元合金催化剂中Pt与Cu的比例为1：1时，催化活性最高。
- 密度泛函理论 /
- Pt_nCu_m(n+m=4) /
- 反应机理 /
- 催化活性 /
- 甲醇
Abstract: The B3PW91/LANL2DZ (ECP) method has been used to calculate the geometric parameters of adsorption and dehydrogenation of methanol on Pt_nCu_m(n+m=4). All the calculations have been used the Gaussian09 program package. Compared the adsorption energy with dehydrogenation energy barrier, it can be concluded that the path of the adsorption of methyl on the Pt site and the C-H broken is the most favorable reaction in all of the possible paths. When the catalyst of Pt_nCu_m (n+m=4) have different Pt and Cu proportions we find the catalytic activity is the best with the Pt and Cu ratio of 1:1.
- density functional theory /
- Pt_nCu_m(n+m=4) /
- reaction mechanism /
- catalytic activity /
- methanol

HTML全文

图 1 CH₃OH在Pt₄上吸附和脱氢过程的势能面

Figure 1 Potential energy profile for the adsorption and dehydrogenation of CH₃OH on Pt₄

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图 2 CH₃OH在Pt₃Cu上吸附和脱氢过程的势能面

Figure 2 Potential energy profile for the adsorption and dehydrogenation of CH₃OH on Pt₃Cu

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图 3 CH₃OH在Pt₂Cu₂上吸附和脱氢过程的势能面

Figure 3 Potential energy profile for the adsorption and dehydrogenation of CH₃OH on Pt₂Cu₂

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图 4 CH₃OH在PtCu₃上吸附和脱氢过程的势能面

Figure 4 Potential energy profile for the adsorpt-ion and dehydrogenation of CH₃OH on PtCu₃

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图 5 CH₃OH在Cu₄上吸附和脱氢过程的势能面

Figure 5 Potential energy profile for the adsorption and dehydrogenation of CH₃OH on Cu₄

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图 6 优化后的几何构型示意图

Figure 6 Optimized geometric configuration

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图 7 CH₃OH在双金属团簇Pt_nCu_m(n+m=4) 上吸附和脱氢的配位效应

Figure 7 Ligand effects on the adsorption and dehydrogenation of CH₃OH on the metallic clusters, Pt_nCu_m(n+m=4)

(a): adsorption energies; (b): dehydrogenation barriers ■: H-Pt; ●: H-Cu; ▲: O-Pt; ▼: O-Cu

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图 8 CH₃OH和Pt_nCu_m(n+m=4) 的Mulliken电荷和前线分子轨道

Figure 8 Frontier molecular orbitals and Mulliken atomic charges of CH₃OH and Pt_nCu_m(n+m=4)

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