title: A single iron site confined in a graphene matrix for the catalytic oxidation of benzene at room temperature.
abstract: Coordinatively unsaturated (CUS) iron sites are highly active in catalytic oxidation reactions; however, maintaining the CUS structure of iron during heterogeneous catalytic reactions is a great challenge. Here, we report a strategy to stabilize single-atom CUS iron sites by embedding highly dispersed FeN4 centers in the graphene matrix. The atomic structure of FeN4 centers in graphene was revealed for the first time by combining high-resolution transmission electron microscopy/high-angle annular dark-field scanning transmission electron microscopy with low-temperature scanning tunneling microscopy. These confined single-atom iron sites exhibit high performance in the direct catalytic oxidation of benzene to phenol at room temperature, with a conversion of 23.4% and a yield of 18.7%, and can even proceed efficiently at 0°C with a phenol yield of 8.3% after 24 hours. Both experimental measurements and density functional theory calculations indicate that the formation of the Fe═O intermediate structure is a key step to promoting the conversion of benzene to phenol. These findings could pave the way toward highly efficient nonprecious catalysts for low-temperature oxidation reactions in heterogeneous catalysis and electrocatalysis.
authors.affiliation: State Key Laboratory of Catalysis, Collaborative Innovation Center of Chemistry for Energy Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, Dalian 116023, China.
authors.forename: Dehui
authors.initials: D
authors.lastname: Deng
authors.affiliation: State Key Laboratory of Catalysis, Collaborative Innovation Center of Chemistry for Energy Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, Dalian 116023, China.
authors.forename: Xiaoqi
authors.initials: X
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Catalysis, Collaborative Innovation Center of Chemistry for Energy Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, Dalian 116023, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Yu
authors.affiliation: SEU-FEI Nano-Pico Center, Key Laboratory of MEMS of Ministry of Education, School of Electronic Science and Engineering, Southeast University, Nanjing 210096, China.
authors.forename: Xing
authors.initials: X
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Catalysis, Collaborative Innovation Center of Chemistry for Energy Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, Dalian 116023, China.
authors.forename: Qingfei
authors.initials: Q
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Catalysis, Collaborative Innovation Center of Chemistry for Energy Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, Dalian 116023, China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Huaixin
authors.initials: H
authors.lastname: Yang
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Huanfang
authors.initials: H
authors.lastname: Tian
authors.affiliation: Canadian Light Source Inc., University of Saskatchewan, 44 Innovation Boulevard, Saskatoon, Saskatchewan S7N 2V3, Canada.
authors.forename: Yongfeng
authors.initials: Y
authors.lastname: Hu
authors.affiliation: Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201204, China.
authors.forename: Peipei
authors.identifier: 0000-0002-8277-8646
authors.initials: P
authors.lastname: Du
authors.affiliation: Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201204, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Si
authors.affiliation: Mössbauer Effect Data Center, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, Dalian 116023, China.
authors.forename: Junhu
authors.initials: J
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Catalysis, Collaborative Innovation Center of Chemistry for Energy Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, Dalian 116023, China.
authors.forename: Xiaoju
authors.initials: X
authors.lastname: Cui
authors.affiliation: State Key Laboratory of Catalysis, Collaborative Innovation Center of Chemistry for Energy Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, Dalian 116023, China.
authors.forename: Haobo
authors.initials: H
authors.lastname: Li
authors.affiliation: State Key Laboratory of Catalysis, Collaborative Innovation Center of Chemistry for Energy Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, Dalian 116023, China.
authors.forename: Jianping
authors.initials: J
authors.lastname: Xiao
authors.affiliation: SEU-FEI Nano-Pico Center, Key Laboratory of MEMS of Ministry of Education, School of Electronic Science and Engineering, Southeast University, Nanjing 210096, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Catalysis, Collaborative Innovation Center of Chemistry for Energy Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, Dalian 116023, China.
authors.forename: Jiao
authors.initials: J
authors.lastname: Deng
authors.affiliation: State Key Laboratory of Catalysis, Collaborative Innovation Center of Chemistry for Energy Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, Dalian 116023, China.
authors.forename: Fan
authors.initials: F
authors.lastname: Yang
authors.affiliation: Department of Chemistry, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada.
authors.forename: Paul N
authors.initials: PN
authors.lastname: Duchesne
authors.affiliation: Department of Chemistry, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada.
authors.forename: Peng
authors.initials: P
authors.lastname: Zhang
authors.affiliation: Canadian Light Source Inc., University of Saskatchewan, 44 Innovation Boulevard, Saskatoon, Saskatchewan S7N 2V3, Canada.
authors.forename: Jigang
authors.initials: J
authors.lastname: Zhou
authors.affiliation: SEU-FEI Nano-Pico Center, Key Laboratory of MEMS of Ministry of Education, School of Electronic Science and Engineering, Southeast University, Nanjing 210096, China.
authors.forename: Litao
authors.initials: L
authors.lastname: Sun
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Jianqi
authors.initials: J
authors.lastname: Li
authors.affiliation: State Key Laboratory of Catalysis, Collaborative Innovation Center of Chemistry for Energy Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, Dalian 116023, China.
authors.forename: Xiulian
authors.identifier: 0000-0002-5906-6675
authors.initials: X
authors.lastname: Pan
authors.affiliation: State Key Laboratory of Catalysis, Collaborative Innovation Center of Chemistry for Energy Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, Dalian 116023, China.
authors.forename: Xinhe
authors.initials: X
authors.lastname: Bao
keywords: Graphene; benzene oxidation; coordinatively unsaturated iron; non-precious catalyst; single atom site