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Title: Acetylene adsorption on δ-MoC(001), TiC(001) and ZrC(001) surfaces: A comprehensive periodic DFT study

A comprehensive study of acetylene adsorption on δ-MoC(001), TiC(001) and ZrC(001) surfaces was carried out by means of calculations based on periodic density functional theory, using the Perdew–Burke–Ernzerhof exchange–correlation functional. It was found that the bonding of acetylene was significantly affected by the electronic and structural properties of the carbide surfaces. The adsorbate interacted with metal and/or carbon sites of the carbide. The interaction of acetylene with the TiC(001) and ZrC(001) surfaces was strong (binding energies higher than $-$3.5 eV), while moderate acetylene adsorption energies were observed on δ-MoC(001) ($-$1.78 eV to –0.66 eV). Adsorption energies, charge density difference plots and Mulliken charges suggested that the binding of the hydrocarbon to the surface had both ionic and covalent contributions. According to the C–C bond lengths obtained, the adsorbed molecule was modified from acetylene-like into ethylene-like on the δ-MoC(001) surface (desired behavior for hydrogenation reactions) but into ethane-like on TiC(001) and ZrC(001). The obtained results suggest that the δ-MoC(001) surface is expected to have the best performance in selective hydrogenation reactions to convert alkynes into alkenes. Another advantage of δ-MoC(001) is that, after C 2H 2 adsorption, surface carbon sites remain available, which are necessary for H 2 dissociation. Furthermore, thesemore » sites were occupied when C 2H 2 was adsorbed on TiC(001) and ZrC(001), limiting their application in the hydrogenation of alkynes.« less
Authors:
 [1] ;  [2] ;  [1] ;  [3] ;  [3]
  1. Univ. de Antioquia UdeA, Medellin (Columbia)
  2. Univ. de Medellin, Medellin (Columbia)
  3. Brookhaven National Lab. (BNL), Upton, NY (United States)
Publication Date:
Report Number(s):
BNL-113747-2017-JA
Journal ID: ISSN 1463-9076; PPCPFQ; R&D Project: CO040; KC0302010; TRN: US1701171
Grant/Contract Number:
SC00112704
Type:
Accepted Manuscript
Journal Name:
Physical Chemistry Chemical Physics. PCCP (Print)
Additional Journal Information:
Journal Name: Physical Chemistry Chemical Physics. PCCP (Print); Journal Volume: 19; Journal Issue: 2; Journal ID: ISSN 1463-9076
Publisher:
Royal Society of Chemistry
Research Org:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
OSTI Identifier:
1351740