title: Facile Enhancement in CO-Tolerance of a Polymer-Coated Pt Electrocatalyst Supported on Carbon Black: Comparison between Vulcan and Ketjenblack.
abstract: The CO poisoning and low durability of the anode platinum electrocatalyst in the direct methanol fuel cell (DMFC) are the two crucial obstacles of the wide commercialization of the DMFC. In this study, we synthesized two different electrocatalysts using VulcanXC-72R (VC) and Ketjenblack (KB) as the carbon supporting material for the methanol oxidation reaction (MOR) and long-term durability test, in which the carbon supporting materials were wrapped by poly[2,2'-(2,6-pyridine)-5,5'-bibenzimidazole] (PyPBI) before the platinum deposition and the fabricated electrocatalysts were coated by the poly(vinylphosphonic acid) (PVPA) via the base-acid reaction. We have found that the as-prepared KB/PyPBI/Pt/PVPA shows a higher durability (7% loss in ECSA) under the potential cycling from 1.0 to 1.5 V vs. RHE compared to that of the VC/PyPBI/Pt/PVPA, which showed a 20% loss in ECSA after 10 000 cycle-durability test. Meanwhile, the KB/PyPBI/Pt/PVPA shows a higher CO tolerance before and after the durability test compared to that of the VC/PyPBI/Pt/PVPA, especially under very high methanol concentration (4 M and 8 M), which is close to the practical application of the DMFC. The observed higher CO tolerance is due to the higher amount of the PVPA (14.6 wt %) in the KB/PyPBI/Pt/PVPA caused by the higher specific surface area of the KB (1232 m(2)/g) compared to the VC (235 m(2)/g).
authors.affiliation: †Department of Applied Chemistry, Graduate School of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.
authors.forename: Zehui
authors.initials: Z
authors.lastname: Yang
authors.affiliation: †Department of Applied Chemistry, Graduate School of Engineering, 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: Shinsuke
authors.initials: S
authors.lastname: Hirata
authors.affiliation: †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: †Department of Applied Chemistry, Graduate School of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.|‡International Institute for Carbon Neutral Energy Research (WPI-I2CNER), Kyushu University, Fukuoka 819-0395, Japan.|§Core Research for Evolutionary Science and Technology (CREST), Japan Science and Technology Agency (JST), 5 Sanbancho, Chiyoda-ku, Tokyo 102-0075, Japan.
authors.forename: Naotoshi
authors.initials: N
authors.lastname: Nakashima
keywords: CO tolerance; Ketjenblack; Vulcan XC-72R; durability; poly(vinylphosphonic acid)