文献类型：期刊文献

中文题名：铜催化草酸二甲酯加氢副产物1,2-丙二醇生成机理的DFT研究

英文题名：A DFT study on the formation mechanism of side product 1,2-propanediol in the hydrogenation of dimethyl oxalate over copper catalyst

作者：伦国栋[1,2];严伟琦[2];周静红[1,2];朱贻安[1,2];李伟[2]

机构：[1]华东理工大学化学工程联合国家重点实验室,上海200237;[2]华东理工大学化工学院,上海200237

年份：2024

卷号：52

期号：4

起止页码：553

中文期刊名：燃料化学学报（中英文）

外文期刊名：Journal of Fuel Chemistry and Technology

收录：CSTPCD;;EI(收录号：20241615939556);Scopus;北大核心:【北大核心2023】；CSCD:【CSCD2023_2024】；

基金：国家重点研发计划(2018YFB0604700);国家自然科学基金(22178102)资助。

语种：中文

中文关键词：草酸二甲酯加氢;Cu催化剂;1,2-丙二醇;密度泛函理论;反应机理

外文关键词：dimethyl oxalate hydrogenation;Cu catalyst;1,2-propanediol;density functional theory;reaction mechanism

摘要：利用密度泛函理论对Cu(111)及Cu_(2)O(111)表面上草酸二甲酯加氢副产物1,2-丙二醇(1,2-PDO)的生成机理进行了探究,计算了两种表面上1,2-PDO生成的不同反应路径基元步骤的热力学数据以及所涉及物种的吸附行为,进行了局域态密度以及差分电荷密度分析,阐明了铜催化剂的主要活性位点及1,2-PDO生成的主要路径。结果表明,1,2-PDO主要由乙二醇和甲醇于Cu_(2)O(111)表面通过Guerbet醇缩合反应生成,具体包括醇脱氢、羟醛缩合以及不饱和醛加氢三个过程。Cu_(2)O(111)表面Cu_(us)^(+)及O_(suf)^(-)位点形成的Lewis酸碱对能够促进反应物、产物及反应中间体的吸附且对于1,2-PDO生成过程的整体催化活性更高。Cu_(2)O(111)表面的O_(suf)^(-)位点是醇类脱氢生成醛、羟醛缩合过程中生成烯醇物种以及不饱和醛类中间体加氢的主要活性中心,而C-C偶联反应则发生在Cu_(us)^(+)金属位点上。论文研究结果可为铜催化剂设计和改性以及草酸酯加氢工艺的优化提供理论指导。
The costly separation of 1,2-propanediol(1,2-PDO),an unavoidable byproduct in the hydrogenation of dimethyl oxalate(DMO),significantly hampers the economic viability of coal-to-ethylene glycol(EG)technology.To address this challenge,the formation mechanism of the side product 1,2-PDO on the Cu(111)and Cu_(2)O(111)surfaces during DMO hydrogenation was investigated,which focused on the active sites of copper catalyst and the dominant pathway through density functional theory calculation.The thermodynamics of each elementary step and the adsorption behavior of various species involved in the reaction network along with the local density of states and charge density difference were systematically analyzed.The results indicate that 1,2-PDO is generated more favorably on the Cu_(2)O(111)surface than that on the Cu(111)surface,owing to the Lewis acid-base pairs,i.e.Cu_(us)^(+)and O_(suf)^(-)sites,present on the Cu_(2)O(111)surface,which strengthens the binding of reactants,products,and reaction intermediates to the substrate.EG reacts primarily with methanol(MeOH)to form 1,2-PDO through Guerbet alcohol condensation reaction through three consecutive steps:alcohol dehydrogenation,aldol condensation,and unsaturated aldehyde hydrogenation.The O_(suf)^(-)sites promote the dehydrogenation of alcohols into aldehydes,the generation of enolates during aldol condensation and the hydrogenation of unsaturated aldehydes,while the Cu_(us)^(+)sites are responsible for the C-C coupling reaction.These findings may shed light on the mechanism of 1,2-PDO formation over Cu catalyst and provide fundamental knowledge for the development of more efficient catalysts and process optimization.