Electrochemical CO₂ reduction reaction (CO₂RR) is a realistic way to achieve carbon neutrality which is essential to mitigate climate change and energy shortage. By using density functional theory based first-principles calculations in this work, we studied the mechanisms of CO₂RR to formic acid (HCOOH), carbon monoxide (CO), and hydrogen (H₂) on 6 indium (In) crystal surfaces, namely (101), (002), (111), (110), (211) and (100), and explored the crystal facet-dependent product selectivity. Based the surface energies calculated for the 6 In surfaces, the Wulff shape of In particle was constructed with 4 surface, namely In (101), (211), (002), and (111). By calculating the Gibbs free energies along 4 reaction pathways for the 3 products of CO₂RR, it was shown that the 6 In surfaces favor either HCOOH or H₂, rather than CO. Especially, the In (101) which dominates the Wulff shape shows good product selectivity for HCOOH, which is in accordance with the result of a recent experiment. Furthermore, the In (110) was predicted as a competitive candidate surface for CO₂RR to HCOOH, but largely ignored before.

电化学CO ₂还原反应(CO ₂ RR) 是实现碳中和的现实方法，这对于缓解气候变化和能源短缺至关重要。通过在这项工作中使用基于密度泛函理论的第一性原理计算，我们研究了 CO ₂ RR 生成甲酸 (HCOOH)、一氧化碳 (CO) 和氢气 (H ₂) 在 6 个铟 (In) 晶面上，即 (101)、(002)、(111)、(110)、(211) 和 (100)，并探索了晶面依赖的产物选择性。基于为 6 In 表面计算的表面能，In 粒子的 Wulff 形状由 4 个表面构成，即 In (101)、(211)、(002) 和 (111)。_{通过计算 CO 2} RR的 3 种产物沿 4 种反应途径的吉布斯自由能，表明 6 In 表面有利于 HCOOH 或 H ₂，而不是 CO。尤其是主导 Wulff 形状的 In (101)对 HCOOH 显示出良好的产物选择性，这与最近的实验结果一致。此外，In (110) 被预测为 CO _{2的竞争候选表面}RR 到 HCOOH，但以前基本上被忽略了。