| 单原子Ge助剂修饰Cu(111)晶面上CO2加氢制甲醇的机理研究 |
| Theoretical investigation on the mechanism of CO2 hydrogenation to methanol over single atom Ge promoter doped Cu(111) surface |
| 作者 | 单位 | E-mail | | 周文武 | 西安科技大学化学与化工学院, 西安 710054
西部煤炭绿色安全开发国家重点实验室(筹), 西安 710054 | Zhww1015@163.com | | 韦晓艺 | 西安科技大学化学与化工学院, 西安 710054 | | | 徐梦宇 | 西安科技大学化学与化工学院, 西安 710054 | | | 樊飞 | 西安科技大学化学与化工学院, 西安 710054 | | | 陈治平 | 西安科技大学化学与化工学院, 西安 710054
西部煤炭绿色安全开发国家重点实验室(筹), 西安 710054 | | | 康洁 | 西安科技大学化学与化工学院, 西安 710054 | | | 张乐 | 西安科技大学化学与化工学院, 西安 710054 | | | 周安宁 | 西安科技大学化学与化工学院, 西安 710054
西部煤炭绿色安全开发国家重点实验室(筹), 西安 710054 | |
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| 摘要: 针对CO2热催化转化制甲醇过程中CO2吸附、活化较困难及副产物较多的问题，提出采用单原子Ge助剂修饰Cu (111)晶面的解决思路，通过密度泛函理论(DFT)计算研究了CO2在Ge-Cu(111)晶面上加氢合成甲醇的反应机理。结果表明，单原子Ge助剂的电子调控增加了与其相邻的Cu原子的电子云密度，使CO2分子在含Ge活性界面上的吸附能力显著增强：CO2在Ge-Cu(111)晶面上的吸附能约为Cu (111)晶面的1.5倍，约为Pd改性Cu(111)晶面的2.4倍，进而使逆水煤气变换(RWGS)反应路径速控步骤的活化能降低了近20 kJ·mol-1，同时衍生出3条生成甲醇的RWGS新路径；此外，Ge-Cu(111)晶面上甲酸盐路径由于速控步骤活化能大幅上升而被禁阻，进而CO及烃类等副产物选择性大幅降低，Ge-Cu(111)晶面上CO2加氢制甲醇选择性升高。 |
| 关键词: 密度泛函理论 Ge-Cu(111)晶面 单原子Ge助剂 CO2加氢制甲醇 电子调控效应 |
| 基金项目: 国家自然科学基金(No.21908174，22178283)和陕西省重点研发计划(No.2020GY-136)资助。 |
| Abstract: In this work, we proposed a novel strategy, doping single atom Ge promoter to the Cu(111) surface, to overcome the shortcomings such as the difficulties in the adsorption and activation of CO2 molecules and the complex by-products produced in both the reverse water gas shift (RWGS) and the formate reaction pathway. The electron modulating effect of single atom Ge species on the reaction mechanism of CO2 hydrogenation to methanol over Ge-Cu(111) surface was detailly investigated by the density functional theory (DFT) method. The results show that the electron supply ability of Cu atoms adjacent to the single Ge atom is greatly enhanced due to the electron modulating effect of Ge species, which leads to the improved interaction between the CO2 molecule and the active interface: the adsorption energy of CO2 over the single atom Ge promoted Cu(111) surface was approximately 1.5 times that over the pure Cu(111) surface and approximately 2.4 times that over clustered Pd modified Cu(111) surface, respectively. The enhanced CO2 adsorption ability further resulted in a decline in the activation energy of the reaction rate control step for the RWGS pathway by about 20 kJ·mol-1, meanwhile, there emerged three new potential RWGS reaction routes that only produced methanol. Moreover, the formate reaction pathway is kinetically inhibited over the Ge-Cu(111) surface, leading to the reduced by-products such as CO and hydrocarbons to improve both the selectivity of methanol in the CO2 hydrogenation to methanol reaction. |
| Keywords: density functional theory Ge-Cu(111) surface single atom Ge promoter CO2 hydrogenation to methanol electron modulating effect |
| 投稿时间：2023-01-09 修订日期：2023-04-07 |
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| 周文武,韦晓艺,徐梦宇,樊飞,陈治平,康洁,张乐,周安宁.单原子Ge助剂修饰Cu(111)晶面上CO2加氢制甲醇的机理研究[J].无机化学学报,2023,39(7):1261-1274. |
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