Preserving Molecular Tuning for Enhanced Electrocatalytic CO2-to-Ethanol Conversion.
Angew Chem Int Ed Engl
; : e202407992, 2024 Aug 14.
Article
en En
| MEDLINE
| ID: mdl-39140436
ABSTRACT
Modifying catalyst surface with small molecular-additives presents a promising avenue for enhancing electrocatalytic performance. However, challenges arise in preserving the molecular-additives and maximizing their tuning effect, particularly at high current-densities. Herein, we develop an effective strategy to preserve the molecular-additives on electrode surface by applying a thin protective layer. Taking 4-dimethylaminopyridine (DMAP) as an example of a molecular-additive, the hydrophobic protection layer on top of the DMAP-functionalized Cu-catalyst effectively prevents its leaching during CO2 electroreduction (CO2R). Consequently, the confined DMAP molecules substantially promote the CO2-to-multicarbon conversion at low overpotentials. For instance, at a potential as low as -0.47 V vs. reversible hydrogen electrode, the DMAP-functionalized Cu exhibits over 80% selectivity towards multi-carbon products, while the pristine Cu shows only ~35% selectivity for multi-carbon products. Notably, ethanol appears as the primary product on DMAP-functionalized Cu, with selectivity approaching 50% at a high current density of 400 mA cm-2. Detailed kinetic analysis, in-situ spectroscopies, and theoretical calculations indicate that DMAP-induced electron accumulations on surface Cu-sites decrease the reaction energy for C-C coupling. Additionally, the interactions between DMAP and oxygenated intermediates facilitate the ethanol formation pathway in CO2R. Overall, this study showcases an effective strategy to guide future endeavors involving molecular tuning effects.
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MEDLINE
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En
Revista:
Angew Chem Int Ed Engl
Año:
2024
Tipo del documento:
Article
País de afiliación:
Singapur