caa a22 4500 445388595 CHVBK 20180317143039.0 cr unu---uuuuu 170323e20111201xx s 000 0 eng 10.1007/s11144-011-0360-x doi (NATIONALLICENCE)springer-10.1007/s11144-011-0360-x Study of Pt/MCM-22 based catalysts in the transformation of n -hexane: effect of rare earth elements and mode of platinum introduction [Elektronische Daten] [Angela Martins, João Silva, Fernando Râmoa Ribeiro, M. Filipa Ribeiro] The bifunctional transformation of n-hexane was carried out over Pt/MCM-22 based catalysts. MCM-22 was synthesized and submitted to ion exchange with rare earth nitrate solutions of La, Nd and Yb, followed by Pt introduction. Three different methods were used to introduce about 1 wt% of Pt in the zeolite: ion exchange, incipient wetness impregnation and mechanical mixture with Pt/Al2O3. The bifunctional catalysts were characterized by transmission electron microscopy and by the model reaction of toluene hydrogenation. These experiments showed that, in the ion exchanged sample, Pt is located both within the inner micropores and on the outer surface, whereas in the impregnated one, the metal is essentially located on the outer surface under the form of large particles. The presence of RE elements increases the hydrogenating activity of Pt/MCM-22 since the location of these species at the vicinity of metal particles causes modification on its electronic properties. Whatever the mode of Pt introduction, a fast initial decrease in conversion is observed for n-hexane transformation, followed by a plateau related to the occurrence of the catalytic transformations at the hemicages located at the outer surface of the crystals. The effect of rare earth elements on the hydrogenating function leads to a lower selectivity in dibranched isomers and increased amounts of light products. Akadémiai Kiadó, Budapest, Hungary, 2011 MCM-22 nationallicence Platinum nationallicence Rare earth elements nationallicence Bifunctional catalyst nationallicence n -hexane nationallicence Martins Angela ADEQ and CIEQB, Instituto Superior de Engenharia de Lisboa, Rua Conselheiro Emídio Navarro, 1, 1959-007, Lisbon, Portugal aut Silva João ADEQ and CIEQB, Instituto Superior de Engenharia de Lisboa, Rua Conselheiro Emídio Navarro, 1, 1959-007, Lisbon, Portugal aut Râmoa Ribeiro Fernando IBB, Instituto Superior Técnico, Av. Rovisco Pais, 1049-001, Lisbon, Portugal aut Filipa Ribeiro M. IBB, Instituto Superior Técnico, Av. Rovisco Pais, 1049-001, Lisbon, Portugal aut Reaction Kinetics, Mechanisms and Catalysis Springer Netherlands 104/2(2011-12-01), 417-428 1878-5190 104:2<417 2011 104 11144 https://doi.org/10.1007/s11144-011-0360-x text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11144-011-0360-x text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Martins Angela ADEQ and CIEQB, Instituto Superior de Engenharia de Lisboa, Rua Conselheiro Emídio Navarro, 1, 1959-007, Lisbon, Portugal aut NATIONALLICENCE 700 1- Silva João ADEQ and CIEQB, Instituto Superior de Engenharia de Lisboa, Rua Conselheiro Emídio Navarro, 1, 1959-007, Lisbon, Portugal aut NATIONALLICENCE 700 1- Râmoa Ribeiro Fernando IBB, Instituto Superior Técnico, Av. Rovisco Pais, 1049-001, Lisbon, Portugal aut NATIONALLICENCE 700 1- Filipa Ribeiro M. IBB, Instituto Superior Técnico, Av. Rovisco Pais, 1049-001, Lisbon, Portugal aut NATIONALLICENCE 773 0- Reaction Kinetics, Mechanisms and Catalysis Springer Netherlands 104/2(2011-12-01), 417-428 1878-5190 104:2<417 2011 104 11144 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer