title: Co-N Decorated Hierarchically Porous Graphene Aerogel for Efficient Oxygen Reduction Reaction in Acid.
abstract: Nitrogen-functionalized graphene materials have been demonstrated as promising electrocatalyst for the oxygen reduction reaction (ORR), owning to their respectable activity and excellent stability in alkaline electrolyte. However, they exhibit unacceptable catalytic activity in acid medium. Here, a hierarchically porous Co-N functionalized graphene aerogel is prepared as an efficient catalyst for the ORR in acid electrolyte. In the preparation process, polyaniline (PANI) is introduced as a pore-forming agent to aid in the self-assembly of graphene species into a porous aerogel networks, and a nitrogen precursor to induce in situ nitrogen doping. Therefore, a Co-N decorated graphene aerogel framework with a large surface area (485 m(2) g(-1)) and an abundance of meso/macropores is effectively formed after heat treatment. Such highly desired structures can not only expose sufficient active sites for the ORR but also guarantee the fast mass transfer in the catalytic process, which provides significant catalytic activity with positive onset and half wave potentials, low hydrogen peroxide yield, high resistance to methanol crossover, and remarkable stability that is comparable to commercial Pt/C in acid medium.
authors.affiliation: Department of Chemical Engineering, Waterloo Institute for Nanotechnology, Waterloo Institute of Sustainable Energy, University of Waterloo , 200 University Ave. W, Waterloo, Ontario N2L 3G1, Canada.
authors.forename: Xiaogang
authors.initials: X
authors.lastname: Fu
authors.affiliation: Department of Chemical Engineering, Waterloo Institute for Nanotechnology, Waterloo Institute of Sustainable Energy, University of Waterloo , 200 University Ave. W, Waterloo, Ontario N2L 3G1, Canada.
authors.forename: Ja-Yeon
authors.initials: JY
authors.lastname: Choi
authors.affiliation: Department of Chemical Engineering, Waterloo Institute for Nanotechnology, Waterloo Institute of Sustainable Energy, University of Waterloo , 200 University Ave. W, Waterloo, Ontario N2L 3G1, Canada.
authors.forename: Pouyan
authors.initials: P
authors.lastname: Zamani
authors.affiliation: Department of Chemical Engineering, Waterloo Institute for Nanotechnology, Waterloo Institute of Sustainable Energy, University of Waterloo , 200 University Ave. W, Waterloo, Ontario N2L 3G1, Canada.
authors.forename: Gaopeng
authors.initials: G
authors.lastname: Jiang
authors.affiliation: Department of Chemical Engineering, Waterloo Institute for Nanotechnology, Waterloo Institute of Sustainable Energy, University of Waterloo , 200 University Ave. W, Waterloo, Ontario N2L 3G1, Canada.
authors.forename: Md Ariful
authors.initials: MA
authors.lastname: Hoque
authors.affiliation: Department of Chemical Engineering, Waterloo Institute for Nanotechnology, Waterloo Institute of Sustainable Energy, University of Waterloo , 200 University Ave. W, Waterloo, Ontario N2L 3G1, Canada.
authors.forename: Fathy Mohamed
authors.initials: FM
authors.lastname: Hassan
authors.affiliation: Department of Chemical Engineering, Waterloo Institute for Nanotechnology, Waterloo Institute of Sustainable Energy, University of Waterloo , 200 University Ave. W, Waterloo, Ontario N2L 3G1, Canada.
authors.forename: Zhongwei
authors.initials: Z
authors.lastname: Chen
keywords: cobalt−nitrogen moieties; fuel cell; graphene aerogel; hierarchically porous structures; oxygen reduction reaction