Main content area

Electrochemical Activation of CO2 through Atomic Ordering Transformations of AuCu Nanoparticles

Kim, Dohyung, Xie, Chenlu, Becknell, Nigel, Yu, Yi, Karamad, Mohammadreza, Chan, Karen, Crumlin, Ethan J., Nørskov, Jens K., Yang, Peidong
Journal of the American Chemical Society 2017 v.139 no.24 pp. 8329-8336
alloys, carbon dioxide, carbon monoxide, catalysts, catalytic activity, copper nanoparticles, electrochemistry, gold, hydrogen production, nanogold
Precise control of elemental configurations within multimetallic nanoparticles (NPs) could enable access to functional nanomaterials with significant performance benefits. This can be achieved down to the atomic level by the disorder-to-order transformation of individual NPs. Here, by systematically controlling the ordering degree, we show that the atomic ordering transformation, applied to AuCu NPs, activates them to perform as selective electrocatalysts for CO₂ reduction. In contrast to the disordered alloy NP, which is catalytically active for hydrogen evolution, ordered AuCu NPs selectively converted CO₂ to CO at faradaic efficiency reaching 80%. CO formation could be achieved with a reduction in overpotential of ∼200 mV, and catalytic turnover was enhanced by 3.2-fold. In comparison to those obtained with a pure gold catalyst, mass activities could be improved as well. Atomic-level structural investigations revealed three atomic gold layers over the intermetallic core to be sufficient for enhanced catalytic behavior, which is further supported by DFT analysis.