Doping S Tailors the Electronic Structure of CuBiOx Catalyst for Selective CO2 Electroreduction to CO

Converting CO 2 into valuable chemicals is a sustainable way to address the energy and environmental crisis, yet achieving high selectivity toward CO remains challenging. Here, a S-doped copper-bismuth oxide (S-CuBiO x ) catalyst with a hierarchical structure was synthesized via a facile solution method toward selectively producing CO from CO 2 . The prepared S-CuBiO x exhibits a 91.3% CO Faradic efficiency at −0.9 V RHE in an H-type cell with 0.5 M KHCO 3 solution, delivering a 3.8-fold enhancement compared to the undoped CuBiO x , while decreasing the H 2 and HCOOH by-products to 2.6% and 4.5%, respectively. The doped-S can be responsible for the excellent CO selectivity, namely, the S dopant induces S-M-O (M = Cu or Bi) bond formation and tunes the local electronic structure of S-CuBiO x , thus benefiting *COOH formation/stabilization and accelerating the reaction kinetics toward CO. This work provides a rational design strategy for steering CO 2 RR selectivity toward CO via non-metal heteroatom doping in bimetallic oxide systems. Graphical The alternative text for this image may have been generated using AI.