title: Probing the catalytic activity of porous graphene oxide and the origin of this behaviour.
abstract: Graphene oxide, a two-dimensional aromatic scaffold decorated by oxygen-containing functional groups, possesses rich chemical properties and may present a green alternative to precious metal catalysts. Graphene oxide-based carbocatalysis has recently been demonstrated for aerobic oxidative reactions. However, its widespread application is hindered by the need for high catalyst loadings. Here we report a simple chemical treatment that can create and enlarge the defects in graphene oxide and impart on it enhanced catalytic activities for the oxidative coupling of amines to imines (up to 98% yield at 5 wt% catalyst loading, under solvent-free, open-air conditions). This study examines the origin of the enhanced catalytic activity, which can be linked to the synergistic effect of carboxylic acid groups and unpaired electrons at the edge defects. The discovery of a simple chemical processing step to synthesize highly active graphene oxide allows the premise of industrial-scale carbocatalysis to be explored.
authors.affiliation: Department of Chemistry, Graphene Research Centre, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore.
authors.forename: Chenliang
authors.initials: C
authors.lastname: Su
authors.forename: Muge
authors.initials: M
authors.lastname: Acik
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Takai
authors.forename: Jiong
authors.initials: J
authors.lastname: Lu
authors.forename: Si-jia
authors.initials: SJ
authors.lastname: Hao
authors.forename: Yi
authors.initials: Y
authors.lastname: Zheng
authors.forename: Pingping
authors.initials: P
authors.lastname: Wu
authors.forename: Qiaoliang
authors.initials: Q
authors.lastname: Bao
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Enoki
authors.forename: Yves J
authors.initials: YJ
authors.lastname: Chabal
authors.forename: Kian Ping
authors.initials: KP
authors.lastname: Loh