title: Incorporation of Nitrogen Defects for Efficient Reduction of CO2 via Two-Electron Pathway on Three-Dimensional Graphene Foam.
abstract: The practical recycling of carbon dioxide (CO2) by the electrochemical reduction route requires an active, stable, and affordable catalyst system. Although noble metals such as gold and silver have been demonstrated to reduce CO2 into carbon monoxide (CO) efficiently, they suffer from poor durability and scarcity. Here we report three-dimensional (3D) graphene foam incorporated with nitrogen defects as a metal-free catalyst for CO2 reduction. The nitrogen-doped 3D graphene foam requires negligible onset overpotential (-0.19 V) for CO formation, and it exhibits superior activity over Au and Ag, achieving similar maximum Faradaic efficiency for CO production (∼85%) at a lower overpotential (-0.47 V) and better stability for at least 5 h. The dependence of catalytic activity on N-defect structures is unraveled by systematic experimental investigations. Indeed, the density functional theory calculations confirm pyridinic N as the most active site for CO2 reduction, consistent with experimental results.
authors.affiliation: Department of Materials Science and NanoEngineering, Rice University , Houston, Texas 77005, United States.
authors.forename: Jingjie
authors.initials: J
authors.lastname: Wu
authors.affiliation: Department of Materials Science and NanoEngineering, Rice University , Houston, Texas 77005, United States.
authors.forename: Mingjie
authors.initials: M
authors.lastname: Liu
authors.affiliation: Department of Chemical Engineering, University of South Carolina , Columbia, South Carolina 29201, United States.
authors.forename: Pranav P
authors.initials: PP
authors.lastname: Sharma
authors.affiliation: Department of Materials Science and NanoEngineering, Rice University , Houston, Texas 77005, United States.
authors.forename: Ram Manohar
authors.initials: RM
authors.lastname: Yadav
authors.affiliation: Department of Materials Science and NanoEngineering, Rice University , Houston, Texas 77005, United States.
authors.forename: Lulu
authors.initials: L
authors.lastname: Ma
authors.affiliation: Department of Materials Science and NanoEngineering, Rice University , Houston, Texas 77005, United States.
authors.forename: Yingchao
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Department of Materials Science and NanoEngineering, Rice University , Houston, Texas 77005, United States.
authors.forename: Xiaolong
authors.initials: X
authors.lastname: Zou
authors.affiliation: Department of Chemical Engineering, University of South Carolina , Columbia, South Carolina 29201, United States.
authors.forename: Xiao-Dong
authors.initials: XD
authors.lastname: Zhou
authors.affiliation: Department of Materials Science and NanoEngineering, Rice University , Houston, Texas 77005, United States.
authors.forename: Robert
authors.initials: R
authors.lastname: Vajtai
authors.affiliation: Department of Materials Science and NanoEngineering, Rice University , Houston, Texas 77005, United States.
authors.forename: Boris I
authors.initials: BI
authors.lastname: Yakobson
authors.affiliation: Department of Materials Science and NanoEngineering, Rice University , Houston, Texas 77005, United States.
authors.forename: Jun
authors.initials: J
authors.lastname: Lou
authors.affiliation: Department of Materials Science and NanoEngineering, Rice University , Houston, Texas 77005, United States.
authors.forename: Pulickel M
authors.initials: PM
authors.lastname: Ajayan
keywords: CO2 reduction; N-doped 3D graphene foam; electrocatalyst; first-principles theory; low overpotential