C−C Bond Scission in Ethane Hydrogenolysis

Abstract

C−C bond scission steps are often considered rate-determining in ethane hydrogenolysis. This paper is devoted to the calculations of the activation energies of these steps using the unity bond index−quadratic exponential potential method, formerly known as the bond-order conservation−Morse potential method. Binding energies of atomic carbon with groups VIII and IB metals Ni(111), Pd(111), Pt(111), Rh(111), Ru(0001), Ir(111), Fe(110), Cu(111), and Au(111) are estimated from experimental data on the chemisorption of various species on these surfaces. The resulting estimates are corrected taking into account DFT data on CH x binding energies. The strengths of carbon binding to the surfaces allow arranging the metals into the following series: Cu(111) < Au(111) < Pd(111) < Ru(0001) < Pt(111) ≈ Ni(111) < Rh(111) < Ir(111) < Fe(110). The values of carbon binding energies range from 122.9 kcal/mol for Cu(111) to 192.5 kcal/mol for Fe(110). The activities of these surfaces toward C−C bond scission increase in the same series.

Mechanism of the Ethylene Conversion to Ethylidyne on Rh(111): A Density Functional Investigation

“…Our calculations confirm the configurations on Rh(111) with the binding energies of 5.67 (hcp) and 5.52 (fcc) eV (see Figure 2), in agreement with the UBI-QEP value (5.46 eV). 49 The C-C bond is tilted by 2°with the length of 1.47 Å, consistent with the values of 2.5°and 1.48 ( 0.04 Å determined in the LEED experiment. 25 Vinyl.…”

Nanostructured ceria supported Pt and Au catalysts for the reactions of ethanol and formic acid

“…Besides, Au also Pt is very active in the WGS reaction [33][34][35][36][37]. As far as ethanol steam reforming is concerned, it is expected that Pt will outperform Au because the former is more active in C C bond breaking reactions [38]. Although Au and Pt nanoparticle catalysts has received considerable attention in the conversion of ethanol [39][40][41][42][43][44][45] and formic acid [22][23][24][25] to useful chemicals and hydrogen, a comparison of the catalytic performances of Pt and Au supported on ceria and the effect of different crystal planes of the ceria support on the activity and selectivity of ethanol and formic acid conversion has not been reported yet.…”

Effect of Sn on the Reactivity of Cu Surfaces

“…9,[11][12][13] Copper-based catalysts are also used in the automobile industry, 14,15 as well as for acrolein synthesis, dehydrogenation of cycloalkanes, and dehydrogenation of alcohols. 14-16 Accordingly, numerous experimental and theoretical studies have been conducted to understand the fundamental surface chemistry of copper, in terms of the adsorption of species such as hydrogen, 17,18 oxygen, [18][19][20] carbon, 21 hydroxyl, 18,22 CO, and NO. 5,20,23 Here, we present a systematic study of the structures and energetics of monatomic (H, O, N, S, and C) and diatomic (CO, NO, and OH) species on Cu(111).…”