The effect of sp² carbon within a boron-doped diamond (BDD) electrode on the electrochemical reduction of CO₂ is investigated for the first time. With increasing sp² content, the Faradaic efficiency for the production of hydrogen (H₂) under constant current density increases while that for the production of formic acid (HCOOH) decreases. Moreover, favorable electrolysis conditions for producing HCOOH shift in the negative potential direction with increasing sp² content. This phenomenon is ascribed to the presence of adsorption sites on the sp² carbon. This work provides guidance for selectively controlling the reduction of CO₂ by adjusting the distribution of carbonaceous species in the BDD electrode.

首次研究了硼掺杂金刚石（BDD）电极中sp ²碳对CO ₂电化学还原的影响。随着sp ²含量的增加，在恒定电流密度下生产氢（H ₂）的法拉第效率提高，而在甲酸（HCOOH）的生产中的法拉第效率降低。而且，随着sp ²含量的增加，用于产生HCOOH的有利的电解条件向负电位方向移动。该现象归因于sp ²碳上存在吸附位点。这项工作为选择性控制CO ₂的还原提供了指导。 通过调节BDD电极中碳质物质的分布。