title: Mechanistic Insights into the Enhanced Activity and Stability of Agglomerated Cu Nanocrystals for the Electrochemical Reduction of Carbon Dioxide to n-Propanol.
abstract: The reduction of carbon dioxide (CO2) to n-propanol (CH3CH2CH2OH) using renewable electricity is a potentially sustainable route to the production of this valuable engine fuel. In this study, we report that agglomerates of ∼15 nm sized copper nanocrystals exhibited unprecedented catalytic activity for this electrochemical reaction in aqueous 0.1 M KHCO3. The onset potential for the formation of n-propanol was 200-300 mV more positive than for an electropolished Cu surface or Cu(0) nanoparticles. At -0.95 V (vs RHE), n-propanol was formed on the Cu nanocrystals with a high current density (jn-propanol) of -1.74 mA/cm(2), which is ∼25× larger than that found on Cu(0) nanoparticles at the same applied potential. The Cu nanocrystals were also catalytically stable for at least 6 h, and only 14% deactivation was observed after 12 h of CO2 reduction. Mechanistic studies suggest that n-propanol could be formed through the C-C coupling of carbon monoxide and ethylene precursors. The enhanced activity of the Cu nanocrystals toward n-propanol formation was correlated to their surface population of defect sites.
authors.affiliation: Department of Chemistry, Faculty of Science, National University of Singapore , 3 Science Drive 3, Singapore 117543.|The Singapore-Berkeley Research Initiative for Sustainable Energy, CREATE Tower 1, Create Way, #11-00, Singapore 138602.
authors.forename: Dan
authors.initials: D
authors.lastname: Ren
authors.affiliation: Department of Chemistry, Faculty of Science, National University of Singapore , 3 Science Drive 3, Singapore 117543.
authors.forename: Nian Tee
authors.initials: NT
authors.lastname: Wong
authors.affiliation: Department of Chemistry, Faculty of Science, National University of Singapore , 3 Science Drive 3, Singapore 117543.|The Singapore-Berkeley Research Initiative for Sustainable Energy, CREATE Tower 1, Create Way, #11-00, Singapore 138602.
authors.forename: Albertus Denny
authors.initials: AD
authors.lastname: Handoko
authors.affiliation: Department of Chemistry, Faculty of Science, National University of Singapore , 3 Science Drive 3, Singapore 117543.
authors.forename: Yun
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Department of Chemistry, Faculty of Science, National University of Singapore , 3 Science Drive 3, Singapore 117543.|The Singapore-Berkeley Research Initiative for Sustainable Energy, CREATE Tower 1, Create Way, #11-00, Singapore 138602.
authors.forename: Boon Siang
authors.initials: BS
authors.lastname: Yeo
keywords: copper nanocrystals; n-propanol; reduction of carbon dioxide