Dealloying-Derived Nanoporous Bismuth for Selective CO Electroreduction to Formate.

Electrochemical CO reduction (COER) to formate is an attractive approach for CO utilization. Here, we report a nanoporous bismuth (np-Bi) catalyst fabricated by chemically dealloying a rapidly solidified MgBi alloy for COER. The np-Bi catalyst exhibits a three-dimensional interconnected ligament-channel network structure, which can efficiently convert CO to formate with a selectivity of ≤94% and an activity of 62 mA cm in a wide potential range. Remarkably, the np-Bi catalyst delivers an industry-level current density of ∼500 mA cm for formate production at a low overpotential of 420 mV in the flow cell. The outstanding COER performance can be attributed to the enlarged surface area with abundant accessible active sites and highly curved surfaces with enhanced intrinsic activity. This work highlights the structural synergies for enhancing COER.