Experimental study reveals enhanced ethylene production using hexoctahedral copper-silver tandem catalysts in electroreduction, indicating high-index facets boost carbon-carbon coupling.
Key Points
To investigate how high-index-faceted copper nanocatalysts integrated with silver foam affect reaction selectivity and carbon-carbon coupling during electrochemical carbon dioxide reduction.
Synthesized tetrahexahedral (THH) and hexoctahedral (HOH) high-index-faceted copper nanoparticles and integrated them with porous silver foam to form tandem electrocatalysts.
Evaluated electroreduction selectivity and tracked reaction intermediates using in situ spectroscopic measurements under operational potentials.
Assessed the morphological stability and catalytic retention of the faceted nanoparticles across various applied potentials.
Ethylene Faradaic efficiency reached a maximum of 60.37% on HOH Cu/Ag, with multicarbon selectivity following the order HOH Cu/Ag > THH Cu/Ag > non-facet-controlled Cu/Ag.
In situ spectroscopy confirmed elevated levels of adsorbed carbon monoxide and coupling intermediates on HOH Cu/Ag within the potential window of optimal ethylene production.
Catalyst structure and selectivity remained stable under moderate potentials, whereas more negative potentials caused surface roughening and performance decay.