Highly Tensile Strained Cu(100) Surfaces by Epitaxial Grown Hexagonal Boron Nitride for CO<sub>2</sub> Electroreduction to C<sub>2+</sub> Products
Qiuwen Liu, Yao Tan, Qin Chen, Xin Zi, Ziwen Mei, Qiyou Wang, Kang Liu, Junwei Fu, Chao Ma, Liyuan Chai, Min Liu
Abstract
Copper (Cu) has been considered as the most promising catalyst for the electrochemical conversion of CO 2 to multicarbon (C 2+ ) products. However, insufficient coverage of the *CO intermediate on the C 2+ formation Cu(100) facet largely hinders the C–C coupling process and thus the C 2+ conversion efficiency. Herein, we developed an epitaxial growth strategy to generate highly tensile-strained Cu(100) facets via the epitaxial growth of hexagonal boron nitride (hBN) on Cu(100) facets to promote *CO coverage for efficient CO 2 to C 2+ conversion. The highest ∼6% tensile strain on the Cu(100) facets was obtained by lattice mismatch between the Cu(100) and hBN(002) facets. Theory calculations indicated that tensile-strained Cu(100) facets deliver a notable d -band center upshift to enhance *CO adsorption. As a result, the obtained highly tensile-strained Cu(100) facets enabled an 8-fold improvement of *CO coverage and thus a 83.4% C 2+ Faradaic efficiency at 1.2 A cm –2 in strongly acidic electrolyte (pH = 1).