Nanoporous Intermetallic Cu<sub>3</sub>Sn/Cu Hybrid Electrodes as Efficient Electrocatalysts for Carbon Dioxide Reduction
Wu‐Bin Wan, Yitong Zhou, Shu‐Pei Zeng, Hang Shi, Ruiqi Yao, Zi Wen, Xingyou Lang, Qing Jiang
Abstract
Abstract Designing highly selective and cost‐effective electrocatalysts toward electrochemical carbon dioxide (CO 2 ) reduction is crucial for desirable transformation of greenhouse gas into fuels or high‐value chemical products. Here, the authors report intermetallic Cu 3 Sn that is in situ formed and seamlessly integrated on self‐supported bimodal nanoporous Cu skeleton (Cu 3 Sn/Cu) via a spontaneous alloying of Sn and Cu as robust electrocatalyst for selective electroreduction of CO 2 to CO. By virtue of Sn atoms strengthening CO adsorption on Cu atoms, the intermetallic Cu 3 Sn has an intrinsic activity of ≈10.58 μA cm −2 , more than 80‐fold higher than that of monometallic Cu. By virtue of hierarchical bicontinuous nanoporous Cu architecture facilitating electron transfer and CO 2 and proton mass transport and offering high specific surface areas for full use of electroactive Cu 3 Sn sites, the nanoporous Cu 3 Sn/Cu hybrid electrodes produce CO at a low overpotential of 0.09 V, and exhibit high partial current density of ≈15 mA cm −2 geo at overpotential of 0.59 V, along with excellent stability and selectivity of 91.5% Faradaic efficiency. The outstanding electrochemical performance make them attractive alternatives to precious Au‐ and Ag‐based electrocatalysts for building low‐cost CO 2 electrolyzers to selectively produce CO.