課題番号 ：S-19-KU-0062
利用形態 ：機器利用
利用課題名（日本語） ：新規カーボンナノチューブ修飾法による用途開発
Program Title (English) ：　Optimization of structural and fabrication parameter of carbon nanotube-based Pt catalyst for highly durable polymer electrolyte fuel cell
利用者名（日本語） ：Weerathunga don Terrence Dhammika
Username (English) ：Weerathunga don Terrence Dhammika
所属名（日本語） ：九州大学ｶｰﾎﾞﾝﾆｭｰﾄﾗﾙ・ｴﾈﾙｷﾞｰ国際研究所
Affiliation (English) ：International Institute for Carbon-Neutral Research, Kyushu University

１．概要（Summary ）
Low durability of PEMFCs is a big issue that needs to be addressed for broad customer acceptance in the market. This study aims to identify a simple physical parameter that can be taken to predict the durability of a carbon nanotube (CNT)-based catalyst composite since CNT-supported composited has proven better durability than carbon black [1].
２．実験（Experimental）
プローブ型顕微ラマン分光測定装置
透過型電子顕微鏡システム
全自動水平型多目的Ｘ線回折装置
ナノ炭素燃料電池評価システム
As CNTs, two multi-walled CNT (Nikkiso and Nanocyl) and two single-walled CNT (eDIPS and Super growth) were selected. Four CNTs were named as Nik, Ncy, eDIPS and SG respectively. Pt nanoparticles (Pt-NPs) were loaded on to the four types of CNTs after coating the CNTs with polybenzimidazole (PBI) based on the previous report [2]. The composites were denoted as Nik/PBI/Pt, Ncy/PBI/Pt, eDIPS/PBI/Pt and SG/PBI/Pt. As the ADT protocol, triangle potential cycling between 1.0 V – 1.5 V vs RHE was performed in order to accelerate the oxidation of carbon.

３．結果と考察（Results and Discussion）
Deterioration of electrochemical surface area (ECSA) was monitored by cyclic voltammetry (CV) and the cycle number (CyN) vs ECSA were plotted.
A relationship was found for the first time between the durability of the CNT supported Pt composites with the thermogravimetric analysis (TGA) on-set temperatures of CNT support materials. Lowest ECSA deterioration was observed in the CNT/Pt composite, which had a low degree of side-wall defects and low C=C bond strain. Therefore, we conclude multi-walled CNTs with large diameters are suitable for highly stable CNT/Pt composites. Furthermore, the onset temperature obtained by TGA of any carbon support or Pt composite can be used as a rough degree of the stability of Pt composites.

[1] Z. Yang, et al, Electrochemica Acta, 170, 1 (2015).
[2] T. Fujigaya, et al, Adv. Mater., 25, 1666 (2013).

４．その他・特記事項（Others）
特になし

５．論文・学会発表（Publication/Presentation）
D. Weerathunga, T. Fujigaya “The relationship between inherent properties of carbon nanotubes and electrochemical durability of supported-Pt catalysts” Diamond & Related Materials. 97, (2019) 107459.

６．関連特許（Patent）
特になし