Surface Reactions of Dicyclohexylmethane on Pt(111)
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- 作者：Christoph Gleichweit ; Max Amende ; Oliver H枚fert ; Tao Xu ; Florian Sp盲th ; Nicole Br眉ckner ; Peter Wasserscheid ; J枚rg Libuda ; Hans-Peter Steinr眉ck ; Christian Papp
- 刊名：Journal of Physical Chemistry C
- 出版年：2015
- 出版时间：September 3, 2015
- 年：2015
- 卷：119
- 期：35
- 页码：20299-20311
- 全文大小：851K
- ISSN：1932-7455
文摘
We investigated the surface reaction of the liquid organic hydrogen carrier dicyclohexylmethane (DCHM) on Pt(111) in ultrahigh vacuum by high-resolution X-ray photoelectron spectroscopy, temperature-programmed desorption, near-edge X-ray absorption fine structure, and infrared reflection鈥揳bsorption spectroscopy. Additionally, the hydrogen-lean molecule diphenylmethane and the relevant molecular fragments of DCHM, methylcyclohexane, and toluene were studied to elucidate the reaction steps of DCHM. We find dehydrogenation of DCHM in the range of 200鈥?60 K, to form a double-sided 蟺-allylic species coadsorbed with hydrogen. Subsequently, 鈭?0% of the molecules desorb, and for 鈭?0%, one of the 蟺-allyls reacts to a phenyl group between 260 and 330 K, accompanied by associative hydrogen desorption. Above 360 K, the second 蟺-allylic species is dehydrogenated to a phenyl ring. This is accompanied by C鈥揌 bond scission at the methylene group, which is an unwanted decomposition step in the hydrogen storage cycle, as it alters the original hydrogen carrier DCHM. Above 450 K, we find further decomposition steps which we assign to C鈥揌 abstraction at the phenyl rings.