Enhanced Electrochemical CO<sub>2</sub> Reduction to Formate over Phosphate‐Modified In: Water Activation and Active Site Tuning
Zhiming Wei, Jie Ding, Ziyi Wang, Anyang Wang, Li Zhang, Yuhang Liu, Yuzheng Guo, Yuzheng Guo, Xuan Yang, Xuan Yang, Yueming Zhai, Yueming Zhai, Bin Liu
Abstract
Abstract Electrochemical CO 2 reduction reaction (CO 2 RR) offers a sustainable strategy for producing fuels and chemicals. However, it suffers from sluggish CO 2 activation and slow water dissociation. In this work, we construct a (P−O) δ− modified In catalyst that exhibits high activity and selectivity in electrochemical CO 2 reduction to formate. A combination of in situ characterizations and kinetic analyses indicate that (P−O) δ− has a strong interaction with K + (H 2 O) n , which effectively accelerates water dissociation to provide protons. In situ attenuated total reflectance surface‐enhanced infrared absorption spectroscopy (ATR‐SEIRAS) measurements together with density functional theory (DFT) calculations disclose that (P−O) δ− modification leads to a higher valence state of In active site, thus promoting CO 2 activation and HCOO* formation, while inhibiting competitive hydrogen evolution reaction (HER). As a result, the (P−O) δ− modified oxide‐derived In catalyst exhibits excellent formate selectivity across a broad potential window with a formate Faradaic efficiency as high as 92.1 % at a partial current density of ~200 mA cm −2 and a cathodic potential of −1.2 V vs. RHE in an alkaline electrolyte.