Achieving high selectivity towards electro-conversion of CO2 using In-doped Bi derived from metal-organic frameworks.

ABSTRACT

Metal-organic frameworks (MOFs) and their derivatives have shown great potential as electrocatalysts, in virtue of their ease of functionalization and abundance of active sites. Here, we report a series of indium-doped bismuth MOF-derived composites (BiInX-Y@C) for the direct conversion of carbon dioxide (CO2) to hydrocarbon derivatives. Amongst the catalysts studied, BiIn5-500@C demonstrated high selectivity for the production of formate and intrinsic activity in a wide potential window, ranging from - 1.16 to - 0.76 V vs. RHE (VRHE). At - 0.86 VRHE, the Faradaic efficiency and total current density were determined as 97.5% and - 13.5 mA cm-2, respectively. In addition, a 15-h stability test shows no obvious signs of deactivation. Complementary density functional theory (DFT) calculations revealed that the In-doped Bi2O3 are the predominant active centers for HCOOH production in the reduction of CO2 under the action of the BiInX-Y@C catalyst. This work provides new detailed insights into reaction mechanism, and selectivity for reduction of CO2via MOFs, which are expected to inspire and guide the design of novel, selective and efficient catalysts.