Harald Kirsch, Yujin Tong and Richard Kramer Campen;
ChemCatChem. 8 (4 ), 728-735 (2016), pp 8;
Catalytic dissociation of hydrocarbons on transition-metal substrates plays a critical role in a variety of industrially important chemistry. Despite this importance, knowledge of the dissociation pathways of even the simplest hydrocarbons on single-metal crystal surfaces in ultrahigh vacuum (UHV) is incomplete. In this study the temperature-induced decomposition of CH4 and C2H4 on Ru(0 0 0 1) is characterized using high-resolution vibrational spectroscopy of all interfacial CH stretch modes. By investigating both decomposition pathways concurrently we are able to unambiguously identify for the first time CCH2(ads) during the decomposition of C2H4, and CH2(ads), CCH3(ads), and CCH(ads) during the decomposition of CH4. Following this identification, the thermal stability of all species is described and also how this stability depends on carbon and hydrogen surface coverage. Although collected in UHV, these observations suggest under-appreciated constraints on the chemistry of CH4 and C2H4 in high-pressure applications.
The original publication is available by link DOI: 10.1002/cctc.201501046