Mesostructure-Induced Selectivity in CO[subscript 2] Reduction Catalysis

Gold inverse opal (Au-IO) thin films are active for CO[subscript 2] reduction to CO with high efficiency at modest overpotentials and high selectivity relative to hydrogen evolution. The specific activity for hydrogen evolution diminishes by 10-fold with increasing porous film thickness, while CO ev...

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Bibliographic Details
Main Authors: Hall, Anthony Shoji, Yoon, Youngmin, Wuttig, Anna, Surendranath, Yogesh
Other Authors: Massachusetts Institute of Technology. Department of Chemistry
Format: Article
Language:en_US
Published: American Chemical Society (ACS) 2016
Online Access:http://hdl.handle.net/1721.1/105469
https://orcid.org/0000-0003-4134-4160
https://orcid.org/0000-0002-8683-975X
https://orcid.org/0000-0001-9519-7907
https://orcid.org/0000-0003-1016-3420
Description
Summary:Gold inverse opal (Au-IO) thin films are active for CO[subscript 2] reduction to CO with high efficiency at modest overpotentials and high selectivity relative to hydrogen evolution. The specific activity for hydrogen evolution diminishes by 10-fold with increasing porous film thickness, while CO evolution activity is largely unchanged. We demonstrate that the origin of hydrogen suppression in Au-IO films stems from the generation of diffusional gradients within the pores of the mesostructured electrode rather than changes in surface faceting or Au grain size. For electrodes with optimal mesoporosity, 99% selectivity for CO evolution can be obtained at overpotentials as low as 0.4 V. These results establish electrode mesostructuring as a complementary method for tuning selectivity in CO[subscript 2] -to-fuels catalysis.