Тип публикации: статья из журнала
Год издания: 2008
Идентификатор DOI: 10.1002/pssb.200844155
Аннотация: The process of hydrogen chemical adsorption on platinum cluster/single wall carbon nanotube (CNT) join surfaces is modelled at various temperatures and pressures. For that, the adsorption energy of hydrogen atoms on surfaces of both platinum (111) plate and CNT (5,5) or (8,8) types is calculated by density functional theory with thПоказать полностьюe PBE approximation. At various temperatures the hydrogen atom hopping rate on both platinum and CNT surfaces is calculated by the transition state theory. Furthermore the hydrogen hopping rate from the platinum surface to the attached nanotube is obtained by calculation of the total energy profile. It is proved that hydrogen atoms can migrate easily at the platinum surface at all temperatures, but at the CNT surface they can migrate beginning at 400-500 K. By calculation of chemical potentials of hydrogen in gas or on CNT or platinum cluster surfaces the equilibrium density of adsorbed hydrogen was calculated at different temperatures and pressures. It is established that for all temperatures in the range 300-900 K and for all pressures less than 500 bar, the hydrogen is dissociated and chemically adsorbed on the platinum surface very effectively, but surface site occupation by hydrogen on attached CNT surface is rather small. But if CNT vacancies are present in the tube structure and the temperature is lower then 450 K, hydrogen atoms can be adsorbed effectively enough on these vacancies. (C) 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Журнал: PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS
Выпуск журнала: Vol. 245, Is. 8
Номера страниц: 1546-1551
ISSN журнала: 03701972
Место издания: WEINHEIM
Издатель: WILEY-V C H VERLAG GMBH