title: DFT simulations and microkinetic modelling of 1-pentyne hydrogenation on Cu20 model catalysts.
abstract: Adsorption and dissociation of H2 and hydrogenation of 1-pentyne on neutral and anionic Cu20 clusters have been investigated using the density functional theory and microkinetic modelling. Molecular adsorption of H2 is found to occur strictly at atop sites. The H2 dimer is activated upon adsorption, and the dissociation occurs with moderate energy barriers. The dissociated H atoms reside preferentially on 3-fold face and 2-fold edge sites. Based on these results, the reaction paths leading to the partial and total hydrogenation of 1-pentyne have been studied step-by-step. The results suggest that copper clusters can display selective activity on the hydrogenation of alkyne and alkene molecules. The hydrogenated products are more stable than the corresponding initial reactants following an energetic staircase with the number of added H atoms. Stable semi-hydrogenated intermediates are formed before the partial (1-pentene) and total (pentane) hydrogenation stages of 1-pentyne. The microkinetic model analysis shows that C5H10 is the dominant product. Increasing the reactants (C5H8/H2) ratio enhances the formation of products (C5H10 and C5H12).
authors.affiliation: COMP Centre of Excellence, Department of Applied Physics, Aalto University, FI-00076 Aalto, Finland; Department of Physics, Tampere University of Technology, P.O. Box 692, FI-33101 Tampere, Finland.
authors.forename: Li
authors.initials: L
authors.lastname: Ma
authors.affiliation: COMP Centre of Excellence, Department of Chemistry, Aalto University, FI-00076 Aalto, Finland.
authors.forename: Marko
authors.initials: M
authors.lastname: Melander
authors.affiliation: COMP Centre of Excellence, Department of Chemistry, Aalto University, FI-00076 Aalto, Finland.
authors.forename: Timo
authors.initials: T
authors.lastname: Weckman
authors.affiliation: COMP Centre of Excellence, Department of Chemistry, Aalto University, FI-00076 Aalto, Finland.
authors.forename: Saana
authors.initials: S
authors.lastname: Lipasti
authors.affiliation: COMP Centre of Excellence, Department of Chemistry, Aalto University, FI-00076 Aalto, Finland.
authors.forename: Kari
authors.initials: K
authors.lastname: Laasonen
authors.affiliation: COMP Centre of Excellence, Department of Applied Physics, Aalto University, FI-00076 Aalto, Finland; Department of Physics, Tampere University of Technology, P.O. Box 692, FI-33101 Tampere, Finland. Electronic address: jaakko.akola@tut.fi.
authors.forename: Jaakko
authors.initials: J
authors.lastname: Akola
mesh_terms: D000480:Alkynes / Q000737:chemistry*; D002384:Catalysis; D003300:Copper / Q000737:chemistry*; D006859:Hydrogen / Q000737:chemistry*; D006865:Hydrogenation; D056004:Molecular Dynamics Simulation; D011789:Quantum Theory; D013816:Thermodynamics
chemical_list: D000480:Alkynes; D003300:Copper; D006859:Hydrogen
keywords: Adsorption and dissociation; Cluster model; Density functional theory; Heterogeneous catalysis; Hydrogenation