著者
北田 暁彦 平島 秀水 小川 淳也 中野 美尚 松本 健俊 中村 潤児
出版者
公益社団法人 日本表面科学会
雑誌
表面科学 = Journal of The Surface Science Society of Japan (ISSN:03885321)
巻号頁・発行日
vol.25, no.9, pp.580-585, 2004-09-10
参考文献数
18

The effect of step-edges on the dissociative adsorption of H<Sub>2</Sub>S has been studied on a Ni(111) surface using scanning tunneling microscopy (STM), Auger electron spectroscopy (AES) and low energy electron diffraction (LEED). Exposure of Ni(111) to H<Sub>2</Sub>S at room temperature results in the formation of S islands with the structures of p(2&times;2) and reconstructed c(5&radic;3&times;9) rect in the vicinity of step-edges. Subsequently, H<Sub>2</Sub>S dissociates on the terrace of Ni(111), leading to the formation of unique S species with a string structure. The STM observation indicates that the dissociation of H<Sub>2</Sub>S takes place on both step-edges and terraces. The dissociative adsorption of CO as well as formation of carbide islands also take place preferentially at the step-edges. It is thus suggested that a small amount of sulfur located at step-edges effectively deactivate CO dissociation in the methanation reaction.
著者
近藤 剛弘 中村 潤児
出版者
一般社団法人 日本真空学会
雑誌
Journal of the Vacuum Society of Japan (ISSN:18822398)
巻号頁・発行日
vol.51, no.4, pp.245-249, 2008 (Released:2008-06-04)
参考文献数
19

Significant improvement of the Pt-electrode in polymer electrolyte fuel cells has been found by replacing the support material from carbon black to multi-walled carbon nanotube (CNT). In order to explore the origin for the better performance of the Pt/CNT catalysts, model studies using Pt nano-particles deposited on a highly oriented pyrolytic graphite (HOPG) have been carried out as a surface science approach. It is suggested that monolayer of Pt nano-particles show a quite different electronic nature, leading to very high catalytic activity.