Synergistic Effect of Metal Doping and Tethered Ligand Promoted High-Selectivity Conversion of CO 2 to C 2 Oxygenates at Ultra-Low Potential

Energy & Environmental Materials

article

Xiaowan Bai¹  Li Shi¹  Qiang Li¹  Chongyi Ling¹  Yixin Ouyang¹  Shiyan Wang¹  Jinlan Wang¹ 

[1] School of Physics, Southeast University

关键词: metal doping;    hydrogen-bonding ligand;    density functional theory;    electrochemical CO2 reduction;    C2 oxygenates selectivity;   

DOI  :  10.1002/eem2.12203

来源: Wiley

【 摘 要 】

Effectively controlling the selectivity of C 2 oxygenates is desirable for electrocatalytic CO 2 reduction. Copper catalyst has been considered as the most potential for reducing CO 2 to C 2 products, but it still suffers from low C 2 selectivity, high overpotential, and competitive hydrogen evolution reaction (HER). Here, we propose a design strategy to introduce a second metal that weakly binds to H and a functional ligand that provides hydrogen bonds and protons to achieve high selectivity of C 2 oxygenates and effective suppression of HER on the Cu(100) surface simultaneously. Seven metals and eleven ligands are screened using first-principles calculations, which shows that Sn is the most efficient for inhibiting HER and cysteamine (CYS) ligand is the most significant in reducing the limiting potential of *CO hydrogenation to *CHO. In the post C−C coupling steps, a so-called “pulling effect” that transfers H in the CYS ligand as a viable proton donor to the C 2 intermediate to form an H bond, can further stabilize the OH group and facilitate the selection of C 2 products toward oxygenates. Therefore, this heterogeneous electrocatalyst can effectively reduce CO 2 to ethanol and ethylene glycol with an ultra-low limiting potential of −0.43 V. This study provides a new strategy for effectively improving the selectivity of C 2 oxygenates and inhibiting HER to achieve advanced electrocatalytic CO 2 reduction.

【 授权许可】

Unknown