Preferentially Stabilizing the Watershed Intermediates by Adsorbate-adsorbate Interaction to Accelerate CO2 Electroreduction to Ethanol

Abstract

Returning CO₂ to liquid ethanol powered by clean energy offers considerable economic benefits and contributes to reaching the goal of carbon neutrality, but it remains a formidable challenge to achieve high ethanol selectivity due to the inevitable strong competition among various pathways. Herein, an investigation is presented to accelerate CO₂ electroreduction to ethanol via preferentially stabilizing the precarious watershed intermediates (^*CHCOH) by creating strong adsorbate-adsorbate interaction. The highly ordered CuOx nanoplates (HO-CuOx NPLs) featuring abundant amorphous-crystalline interface exhibit an exceptional ethanol Faradaic efficiency (FE_EtOH) of 63.8% and an ethanol-to-ethylene ratio of 6.1 at a large ethanol partial current density (j_ethanol) of 232.8 mA cm⁻². The findings decipher that abundant in-between nanogaps in the amorphous-crystalline interface enhance the adsorption of ^*OH, which can preferentially strengthen C─O bonds while weakening the Cu─C interaction of ^*CHCOH through adsorbate-adsorbate interaction, thereby enabling a predilection for CO₂ to ethanol conversion. Beyond an efficient ethanol-oriented CO₂RR electrocatalyst, the investigations provide an in-depth understanding of adsorbate-adsorbate interaction on key CO₂RR steps and precise intermediates regulation, which can be extended to a range of energy conversion technologies.