Open AccessBoosting Formate Production from CO 2 at High Current Densities Over a Wide Electrochemical Potential Window on a SnS Catalyst
Author(s) -
Zou Jinshuo,
Lee ChongYong,
Wallace Gordon G.
Publication year - 2021
Publication title -
advanced science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.388
H-Index - 100
ISSN - 2198-3844
DOI - 10.1002/advs.202004521
Subject(s) - electrolyte , alkalinity , faraday efficiency , formate , electrochemistry , catalysis , hydrogen production , electrolysis , materials science , electrode , bulk electrolysis , reversible hydrogen electrode , inorganic chemistry , electrolysis of water , hydrogen , chemical engineering , current density , electrocatalyst , chemistry , working electrode , organic chemistry , quantum mechanics , engineering , physics
The flow‐cell design offers prospect for transition to commercial‐relevant high current density CO 2 electrolysis. However, it remains to understand the fundamental interplay between the catalyst, and the electrolyte in such configuration toward CO 2 reduction performance. Herein, the dramatic influence of electrolyte alkalinity in widening potential window for CO 2 electroreduction in a flow‐cell system based on SnS nanosheets is reported. The optimized SnS catalyst operated in 1 m KOH achieves a maximum formate Faradaic efficiency of 88 ± 2% at −1.3 V vs reversible hydrogen electrode (RHE) with the current density of ≈120 mA cm −2 . Alkaline electrolyte is found suppressing the hydrogen evolution across all potentials which is particularly dominant at the less negative potentials, as well as CO evolution at more negative potentials. This in turn widens the potential window for formate conversion (>70% across −0.5 to −1.5 V vs RHE). A comparative study to SnO x counterpart indicates sulfur also acts to suppress hydrogen evolution, although electrolyte alkalinity resulting in a greater suppression. The boosting of the electrochemical potential window, along with high current densities in SnS derived catalytic system offers a highly attractive and promising route toward industrial‐relevant electrocatalytic production of formate from CO 2 .