Structure, reactivity, and mobility of carbonaceous overlayers during olefin hydrogenation on platinum and rhodium single crystal surfaces

Autor:	Anderson L. Marsh, Gabor A. Somorjai
Rok vydání:	2005
Předmět:	Olefin fiber Chemistry Cyclohexene chemistry.chemical_element General Chemistry Photochemistry Catalysis Rhodium Overlayer Metal chemistry.chemical_compound visual_art visual_art.visual_art_medium Dehydrogenation Platinum
Zdroj:	Topics in Catalysis. 34:121-128
ISSN:	1572-9028 1022-5528
Popis:	The hydrogenation of olefins (ethylene, propylene, and isobutene) and a cyclic olefin (cyclohexene) has been characterized on platinum and rhodium single crystal surfaces under conditions ranging from ultrahigh vacuum (UHV) to elevated pressures. A carbonaceous overlayer, formed by C–H bond activation, exists on the metal surface during catalytic hydrogenation, and the structure of this overlayer has been characterized using sum frequency generation (SFG) vibrational spectroscopy. The dehydrogenated carbonaceous species are unreactive even in the presence of excess hydrogen, while the intermediates that turnover are weakly bonded to the metal surface. The formation of this carbonaceous overlayer is accompanied by a restructuring of the metal surface. The overlayer is mobile on the surface during hydrogenation, as shown by high pressure scanning tunneling microscopy (HP-STM) results. Coadsorbed CO induces ordered surface structures, and as a consequence poisons the reaction.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::bc882b6ede0242c695f104ac1baa9445 https://doi.org/10.1007/s11244-005-3805-5 Zobrazit plný text záznamu Plný text ve formátu PDF