Structure and reactions of carbon and hydrogen on Ru(0001): A scanning tunneling microscopy study

Abstract

The interaction between carbon and hydrogen atoms on a Ru(0001) surface was studied using scanning tunneling microscopy (STM), Density Functional Theory (DFT) and STM image calculations.Formation of CH species by reaction between adsorbed H and C was observed to occur readily at 100 K.When the coverage of H increased new complexes of the form CH+nH (n = 1, 2 and 3) were observed. These complexes, never observed before, might be precursors for further hydrogenation reactions. DFT analysis reveals that a considerable energy barrier exists for the CH+H CH 2 reaction. * Current address: Surface Chemistry Lab., RIKEN (The institute of physical and chemical research), 2-

First-Principles Investigation of C–H Bond Scission and Formation Reactions in Ethane, Ethene, and Ethyne Adsorbed on Ru(0001)

“…31,42 Shimizu et al used scanning tunneling microscopy at 100 K to directly follow this reaction. 42 However, the activation energy proposed by Shimizu et al (0.26 eV) is almost four times lower than the one reported by Barteau et al (0.95 eV). We report an activation energy of about 0.83 eV (Table 2, R.10) which is close to the value of Barteau et al, and the discrepancy could be due to the different initial coverages in the experiments.…”

Controlling CH 2 dissociation on Ru(0001) through surface site blocking by adsorbed hydrogen

“…This clarifies why CH 2 and/or CH 3 were observed after decomposition of hydrocarbons, but only CH could be found when hydrogenating atomic carbon at the Ru surface [47]. Prior work on Fischer-Tropsch synthesis has argued for the importance of CH or C as the C 1 building block of longer chain growth, based at least in part on calculations assuming the absence of abundant, non-equilibrium, coadsorbed hydrogen, and on experiments that do not quantify the presence of surface coadsorbed H. Our results suggest that considering such surface H leads to re-evaluation of the stability of CH 2 relative to other CH x surface radicals and support the idea of the enhanced role for this species in the Fischer-Tropsch process [48].…”

Providing Fundamental and Applied Insights into Fischer–Tropsch Catalysis: Sasol–Eindhoven University of Technology Collaboration

“…Information on hydrocarbon chemistry , i.e., chain growth and chain termination steps that speak primarily to selectivity , on the other hand, is typically only available for C1 and C2 intermediates, products that show a typical selectivity behavior in applied FTS. In addition, experimental literature covers only a small selection of Ni and Ru surface geometries; very little information is available for cobalt surfaces, − while experimental studies on iron carbide systems are completely absent. However, the study of hydrocarbon reactions on surfaces has recently demonstrated value for understanding FTS catalysis.…”