Strategy for Enhancing Catalytic Active Site: Introduction of 1D material InSeI for Electrochemical CO Reduction to Formate.

The presence of oxygen vacancies (V) in electrocatalysts plays a significant role in improving the selectivity and activity of CO reduction reaction (CORR). In this study, 1D material with large surface area is utilized to enable uniform V formation on the catalyst. 1D structured indium selenoiodide (InSeI) is synthesized and used as an electrocatalyst for the conversion of CO to formate. The electrochemical treatment of InSeI leads to the leaching of Se and I from the catalyst surface and the formation of V. The resulting V promotes the activity of the CORR, which increases the local pH of the catalyst surface and chemically maintains the oxidized metal sites on the catalyst. Owing to these characteristics, activated In wire exhibited remarkable CORR activity, thereby surpassing 93% FE at 500 mA cm, with a maximum of 97.3% FE at 100 mA cm. Moreover, the catalytic activity remained consistent for over 50 h at 100 mA cm (FE >88%). Thus, the findings imply that using 1D materials can facilitate the formation of oxygen vacancies on the catalyst surface and improve the selectivity and durability of CORR. This indicates the potential for further research on 1D materials as electrocatalysts.