Cu(110)晶面催化还原CO_(2)制备甲酸机理的第一性原理研究  

First principles study on the catalytic reduction mechanism ofCO_(2) to formic acid on Cu(110)crystal surface

作　　者：张旭昀[1] 汤静 常庆 王勇[1] 谭秀娟[1] ZHANG Xuyun;TANG Jing;CHANG Qing;WANG Yong;TAN Xiujuan(School of Mechanical Science and Engineering,Northeast Petroleum University,Daqing 163318,China)

机构地区：[1]东北石油大学机械科学与工程学院,黑龙江大庆163000

出　　处：《功能材料》2024年第4期4102-4110,共9页Journal of Functional Materials

基　　金：黑龙江省自然科学基金(LH2023E016);国家自然科学基金(51974091)。

摘　　要：铜基催化剂是一种高效还原CO_(2)为甲酸的绿色催化剂,明确不同晶面的还原机理对催化剂的设计及开发具有重要指导意义,但Cu(110)晶面的催化机理尚不明确。采用基于密度泛函理论的第一性原理方法对Cu(110)表面的还原机理进行了研究,系统研究了不同中间产物的吸附相关性质并探讨了相关的吸附机理。吸附能结果表明,CO_(2)在Cu(110)表面无法发生化学吸附,而^(*)COOH、^(*)HCOO、HCOOH分子和H原子的最稳定吸附位点分别为长桥位点、短桥位点、顶位点和HCP位点。布居数结果表明,^(*)HCOO和HCOOH分子在吸附过程中与Cu(110)表面的Cu原子形成离子键,H原子和Cu原子之间存在氢键作用,^(*)COOH分子中的C和Cu原子形成共价键。此外,电子态密度结果表明^(*)HCOO基团和Cu原子之间形成O—Cu键,^(*)COOH基团中的C和Cu原子形成C—Cu键,HCOOH分子中的O和Cu原子形成O—Cu键。相比于^(*)COOH/Cu(110)体系,^(*)HCOO/Cu(110)吸附体系的电荷密度、电荷转移量和成键能力均较强,说明CO_(2)在Cu(110)还原过程中中间体^(*)HCOO更稳定,合成路径属于更加高效的:CO_(2)→^(*)HCOO→HCOOH路径。Copper-based catalysts are efficient green catalysts for the reduction of CO_(2) to formic acid.Understanding the reduction mechanisms on different crystal surfaces is of significant importance for the design and development of catalysts.However,the catalytic mechanism on the Cu(110)crystal surface remains unclear.In this study,we employed first-principles methods based on density functional theory to investigate the reduction mechanism on the Cu(110)surface.We systematically studied the adsorption properties of various intermediate products and explored the corresponding adsorption mechanisms.The adsorption energy results indicate that CO_(2) cannot chemically adsorb on the Cu(110)surface.Instead,the most stable adsorption sites for^(*)COOH,^(*)HCOO,HCOOH molecules,and H atoms are the long-bridge site,short-bridge site,top site,and HCP site,respectively.Population analysis results show that^(*)HCOO and HCOOH molecules form ionic bonds with Cu atoms on the Cu(110)surface during the adsorption process,while there is a hydrogen bond interaction between H atoms and Cu atoms.In the case of^(*)COOH molecules,a covalent bond forms between the C and Cu atoms.Additionally,electronic density of states results indicate the formation of O—Cu bonds between^(*)HCOO groups and Cu atoms,C—Cu bonds between C and Cu atoms in^(*)COOH molecules,and O—Cu bonds between O and Cu atoms in HCOOH molecules.Furthermore,compared to the^(*)COOH/Cu(110)system,the^(*)HCOO/Cu(110)adsorption system exhibits stronger charge density,charge transfer,and bonding capability.This suggests that the intermediate^(*)HCOO is more stable during the CO_(2) reduction process on Cu(110),indicating a more efficient synthesis pathway:CO_(2)→^(*)HCOO→HCOOH.

关 键 词：电催化 二氧化碳还原 甲酸 第一性原理 铜基催化剂 

分 类 号：O641.1[理学—物理化学] O647.3[理学—化学]