In situ revealing C–C coupling behavior for CO ₂ electroreduction on tensile strain Pt ^{<i>δ</i> +} –Cu ^{<i>δ</i> +} dual sites

Abstract

Abstract Engineering the desired dual metal sites to realize C–C coupling of CO 2 is of great importance for the practical applications of CO 2 electroreduction reaction (CER). Herein, an efficient strategy for constructing heterogeneous Pt δ + –Cu δ + dual sites to strengthen the generation and coupling of *CO and *CHO (or *COH) during CER process is presented in this work. The radii‐larger Pt not only stabilizes the Cu δ + but also induces a tensile strain in Pt δ + –Cu δ + dual sites. The obtained Pt δ + –Cu δ + dual sites achieve a total Faradaic efficiency and current density of C 2 products with 70.9% and 586.9 mA·cm −2 at – 1.20 V (vs. RHE), which is higher than that of Cu δ + single site (55.4%, 286.9 mA·cm −2 ). The in situ attenuated total reflection surface‐enhanced infrared absorption spectroscopy (ATR‐SEIRAS) reveals that the Pt δ + –Cu δ + dual sites can promote the generation of C 1 intermediates (such as *CO, *COOH, *COH, and *CHO) and C–C coupling. Additional in situ surface‐enhanced Raman spectra demonstrate that Pt δ + –Cu δ + dual sites can induce the generation of the high‐frequency peak for *CO atop , thus accelerating the C–C coupling. This work provides a promising avenue for stabilizing and enhancing the performance of Cu δ + sites toward CER.