The lack of efficient electrocatalysts has been a main obstacle for the large-scale commercialization of CO₂ electroreduction. In this work, we demonstrate that two-dimensional (2D) β-PdBi₂ monolayer is a promising solution for this issue. β-PdBi₂ monolayer is a stable 2D crystal, and the three-dimensional bulk interlayer energy is similar as for other layered materials that can be exfoliated into 2D crystals. Interestingly, β-PdBi₂ monolayer has rather intriguing electronic properties: while being metallic, it also has a non-trivial topological point. Remarkably, the extra electronic states at the Fermi level induced by the intrinsic spin-orbit coupling effect significantly enhance the adsorption of OCHO∗ intermediate on β-PdBi₂ monolayer, resulting in a rather small onset potential of −0.26 V vs. RHE for CO₂ electroreduction to HCOOH. These results not only suggest a promising candidate for CO₂ electrolysis but also deepen our understanding of the factors dominating the catalytic activity of 2D materials.

缺乏有效的电催化剂一直是CO ₂电还原大规模商业化的主要障碍。在这项工作中，我们证明了二维（2D）β-PdBi ₂单层是针对此问题的可行的解决方案。β-PdBi ₂单层是一种稳定的晶体2D，和三维堆积层间能量是作为可剥离成二维晶体其它层状材料相似。有趣的是，β-PdBi ₂单层已经相当耐人寻味电子性质：，同时金属外，还具有一个非平凡拓扑点。值得注意的是，固有自旋轨道耦合效应在费米能级上产生的额外电子态显着增强了OCHO *中间体在β-PdBi上的吸附。₂单层，相对于RHE，CO ₂电还原为HCOOH的起始电位为-0.26V 。这些结果不仅表明有希望用于CO ₂电解，而且还加深了我们对主导2D材料催化活性的因素的理解。