title: Growth and Deposition of Au Nanoclusters on Polymer-wrapped Graphene and Their Oxygen Reduction Activity.
abstract: The development of a non-Pt electrocatalyst with a high performance for the oxygen reduction reaction (ORR) is one of the central issues in polymer electrolyte fuel cells science. Au-nanoparticles (Au-NPs) with a diameter of <2 nm are one of the promising substitutes of Pt-NPs; however, it is still a challenge to synthesize such a small-sized Au-NPs with a narrow diameter distribution on a carbon support without using capping agents. We here describe a facile method to deposit uniform Au-NPs (diameter = 1.6 nm and 3.3 nm) on the stacked-graphene (<10 layers) coated with poly[2,2'-(2,6-pyridine)-5,5'-bibenzimidazole] without using any capping agents. The obtained Au-NPs exhibit an excellent ORR activity with the onset potential at -0.11 V and -0.09 V (vs. Ag/AgCl) for 1.6 nm and 3.3 nm, respectively. On the other hand, inhomogeneous Au-NPs with 4.6 nm in average diameter shows the onset potential at -0.15 V (vs. Ag/AgCl).
authors.affiliation: International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, 744 Motooka Nishi-ku, Fukuoka 819-0395, Japan.|Department of Applied Chemistry, Graduate School of Engineering, Kyushu University, 744 Motooka Nishi-ku, Fukuoka 819-0395, Japan.
authors.forename: Tsuyohiko
authors.initials: T
authors.lastname: Fujigaya
authors.affiliation: International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, 744 Motooka Nishi-ku, Fukuoka 819-0395, Japan.
authors.forename: ChaeRin
authors.initials: C
authors.lastname: Kim
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Kyushu University, 744 Motooka Nishi-ku, Fukuoka 819-0395, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Hamasaki
authors.affiliation: International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, 744 Motooka Nishi-ku, Fukuoka 819-0395, Japan.|Department of Applied Chemistry, Graduate School of Engineering, Kyushu University, 744 Motooka Nishi-ku, Fukuoka 819-0395, Japan.|JST-CREST, 5 Sanbancho, Chiyoda-ku, Tokyo, 102-0075, Japan.
authors.forename: Naotoshi
authors.initials: N
authors.lastname: Nakashima