Improved CO2 reduction activity towards C2+ alcohols on a tandem gold on copper electrocatalyst

Authors: 
Carlos G. Morales-Guio, Etosha R. Cave, Stephanie A. Nitopi, Jeremy T. Feaster, Lei Wang, Kendra P. Kuhl, Ariel Jackson, Natalie C. Johnson, David N. Abram, Toru Hatsukade, Christopher Hahn, Thomas F. Jaramillo
Year of publication: 
2018
Journal: 
Nature Catalysis

The discovery of materials for the electrochemical transformation of carbon dioxide into liquid fuels has the potential to impact large-scale storage of renewable energies and reduce carbon emissions. Here, we report the discovery of an electrocatalyst composed of gold nanoparticles on a polycrystalline copper foil (Au/Cu) that is highly active for CO2 reduction to alcohols. At low overpotentials, the Au/Cu electrocatalyst is over 100 times more selective for the formation of products containing C–C bonds versus methane or methanol, largely favouring the generation of alcohols over hydrocarbons. A combination of electrochemical testing and transport modelling supports the hypothesis that CO2 reduction on gold generates a high CO concentration on nearby copper, where CO is further reduced to alcohols such as ethanol and n-propanol under locally alkaline conditions. The bimetallic Au/Cu electrocatalyst exhibits synergistic activity and selectivity superior to gold, copper or AuCu alloys, and opens new possibilities for the development of CO2 reduction electrodes exploiting tandem catalysis mechanisms.

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