Unveiling hydrocerussite as an electrochemically stable active phase for efficient carbon dioxide electroreduction to formate

Abstract

For most metal-containing CO ₂ reduction reaction (CO ₂RR) electrocatalysts, the unavoidable self-reduction to zero-valence metal will promote hydrogen evolution, hence lowering the CO ₂RR selectivity. Thus it is challenging to design a stable phase with resistance to electrochemical self-reduction as well as high CO ₂RR activity. Herein, we report a scenario to develop hydrocerussite as a stable and active electrocatalyst via in situ conversion of a complex precursor, tannin-lead(II) (TA-Pb) complex. A comprehensive characterization reveals the in situ transformation of TA-Pb to cerussite (PbCO ₃), and sequentially to hydrocerussite (Pb ₃(CO ₃) ₂(OH) ₂), which finally serves as a stable and active phase under CO ₂RR condition. Both experiments and theoretical calculations confirm the high activity and selectivity over hydrocerussite. This work not only offers a new approach of enhancing the selectivity in CO ₂RR by suppressing the self-reduction of electrode materials, but also provides a strategy for studying the reaction mechanism and active phases of electrocatalysts.

Abstract

While electrochemical CO2 reduction represents a renewable means to produce high-value products, catalyst transformation may compete with desirable processes. Here, authors prevent catalyst self-reduction during CO2 electroreduction and show stable, formate-selective performances of hydrocerussite.