Highly Tensile Strained Cu(100) Surfaces by Epitaxial Grown Hexagonal Boron Nitride for CO<sub>2</sub> Electroreduction to C<sub>2+</sub> Products.

Liu, Qiuwen; Tan, Yao; Chen, Qin; Zi, Xin; Mei, Ziwen; Wang, Qiyou; Liu, Kang; Fu, Junwei et al. · Nano Lett · 2024

basic_science · Level V

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Abstract

Copper (Cu) has been considered as the most promising catalyst for the electrochemical conversion of CO<sub>2</sub> to multicarbon (C<sub>2+</sub>) products. However, insufficient coverage of the *CO intermediate on the C<sub>2+</sub> formation Cu(100) facet largely hinders the C-C coupling process and thus the C<sub>2+</sub> 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<sub>2</sub> to C<sub>2+</sub> 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 <i>d</i>-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<sub>2+</sub> Faradaic efficiency at 1.2 A cm<sup>-2</sup> in strongly acidic electrolyte (pH = 1).