caa a22 4500 605513600 CHVBK 20210128100701.0 cr unu---uuuuu 210128e20151101xx s 000 0 eng 10.1007/s00894-015-2828-5 doi (NATIONALLICENCE)springer-10.1007/s00894-015-2828-5 The CO oxidation mechanism on small Pd clusters. A theoretical study [Elektronische Daten] [Julio González-Torres, Virineya Bertin, Enrique Poulain, Oscar Olvera-Neria] CO is a pollutant that is removed by oxidation using Pd, Pt or Rh as catalysts in the exhaust pipes of vehicles. Here, a quantum chemistry study on the CO + O2 reaction catalyzed by small Pdn clusters (n ≤ 5) using the PBE/TZ2P/ZORA method is performed. The limiting step in this reaction at low temperature and coverage is the O2 dissociation. Pdn clusters catalyze the O=O bond breaking, reducing the energy barrier from 119 kcal mol-1 without catalyst to ∼35 kcal mol-1. The charge transfer from Pd to the O2,ad antibonding orbital weakens, and finally breaks the O─O bond. The CO oxidation takes place by the Eley-Rideal (ER) mechanism or the Langmuir-Hinshelwood (LH) mechanism. The ER mechanism presents an energy barrier of 4.10-7.05 kcal mol-1 and the formed CO2 is released after the reaction. The LH mechanism also shows barrier energies to produce CO2 (7-15 kcal mol-1) but it remains adsorbed on Pd clusters. An additional energy (7-25 kcal mol-1) is necessary to desorb CO2 and release the metal site. The triplet multiplicity is the ground states of studied Pdn clusters, with the following order of stability: triplet > singlet > quintet state. Graphical Abstract CO oxidation mechanism on small Pd clusters Springer-Verlag Berlin Heidelberg, 2015 CO oxidation nationallicence DFT/ZORA method nationallicence Eley-Rideal mechanism nationallicence Langmuir-Hinshelwood mechanism nationallicence O2 dissociation nationallicence Pd clusters nationallicence González-Torres Julio Área de Física Atómica Molecular Aplicada (FAMA), CBI, Universidad Autónoma Metropolitana-Azcapotzalco, Av. San Pablo 180, Col. Reynosa Tamaulipas, 02200, Mexico, DF, Mexico aut Bertin Virineya Departamento de Química, Universidad Autónoma Metropolitana-Iztapalapa, San Rafael Atlixco 186, Col. Vicentina, 09340, Mexico, DF, Mexico aut Poulain Enrique Área de Física Atómica Molecular Aplicada (FAMA), CBI, Universidad Autónoma Metropolitana-Azcapotzalco, Av. San Pablo 180, Col. Reynosa Tamaulipas, 02200, Mexico, DF, Mexico aut Olvera-Neria Oscar Área de Física Atómica Molecular Aplicada (FAMA), CBI, Universidad Autónoma Metropolitana-Azcapotzalco, Av. San Pablo 180, Col. Reynosa Tamaulipas, 02200, Mexico, DF, Mexico aut Journal of Molecular Modeling Springer Berlin Heidelberg 21/11(2015-11-01), 1-10 1610-2940 21:11<1 2015 21 894 https://doi.org/10.1007/s00894-015-2828-5 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00894-015-2828-5 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- González-Torres Julio Área de Física Atómica Molecular Aplicada (FAMA), CBI, Universidad Autónoma Metropolitana-Azcapotzalco, Av. San Pablo 180, Col. Reynosa Tamaulipas, 02200, Mexico, DF, Mexico aut NATIONALLICENCE 700 1- Bertin Virineya Departamento de Química, Universidad Autónoma Metropolitana-Iztapalapa, San Rafael Atlixco 186, Col. Vicentina, 09340, Mexico, DF, Mexico aut NATIONALLICENCE 700 1- Poulain Enrique Área de Física Atómica Molecular Aplicada (FAMA), CBI, Universidad Autónoma Metropolitana-Azcapotzalco, Av. San Pablo 180, Col. Reynosa Tamaulipas, 02200, Mexico, DF, Mexico aut NATIONALLICENCE 700 1- Olvera-Neria Oscar Área de Física Atómica Molecular Aplicada (FAMA), CBI, Universidad Autónoma Metropolitana-Azcapotzalco, Av. San Pablo 180, Col. Reynosa Tamaulipas, 02200, Mexico, DF, Mexico aut NATIONALLICENCE 773 0- Journal of Molecular Modeling Springer Berlin Heidelberg 21/11(2015-11-01), 1-10 1610-2940 21:11<1 2015 21 894