title: Exceptional size-dependent activity enhancement in the electroreduction of CO2 over Au nanoparticles.
abstract: The electrocatalytic reduction of CO2 to industrial chemicals and fuels is a promising pathway to sustainable electrical energy storage and to an artificial carbon cycle, but it is currently hindered by the low energy efficiency and low activity displayed by traditional electrode materials. We report here the size-dependent catalytic activity of micelle-synthesized Au nanoparticles (NPs) in the size range of ∼1-8 nm for the electroreduction of CO2 to CO in 0.1 M KHCO3. A drastic increase in current density was observed with decreasing NP size, along with a decrease in Faradaic selectivity toward CO. Density functional theory calculations showed that these trends are related to the increase in the number of low-coordinated sites on small NPs, which favor the evolution of H2 over CO2 reduction to CO. We show here that the H2/CO product ratio can be specifically tailored for different industrial processes by tuning the size of the catalyst particles.
authors.affiliation: Department of Physics, University of Central Florida , Orlando, Florida 32816, United States.
authors.forename: Hemma
authors.initials: H
authors.lastname: Mistry
authors.forename: Rulle
authors.initials: R
authors.lastname: Reske
authors.forename: Zhenhua
authors.initials: Z
authors.lastname: Zeng
authors.forename: Zhi-Jian
authors.initials: ZJ
authors.lastname: Zhao
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Greeley
authors.forename: Peter
authors.initials: P
authors.lastname: Strasser
authors.forename: Beatriz Roldan
authors.initials: BR
authors.lastname: Cuenya