Selective oxidation of 5-hydroxymethylfurfural using monometallic and bimetallic supported nanoparticles

Lolli, Alice (2015) Selective oxidation of 5-hydroxymethylfurfural using monometallic and bimetallic supported nanoparticles, [Dissertation thesis], Alma Mater Studiorum Università di Bologna. Dottorato di ricerca in Chimica, 27 Ciclo. DOI 10.6092/unibo/amsdottorato/6924.
Documenti full-text disponibili:
[img]
Anteprima
Documento PDF (English) - Richiede un lettore di PDF come Xpdf o Adobe Acrobat Reader
Download (5MB) | Anteprima

Abstract

This work deals with the oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) using metal supported catalysts. Catalysts were prepared from the immobilisation of preformed monometallic (Au, Pd) and bimetallic (AuCu, AuPd) nanoparticles on commercial oxides (TiO2, CeO2). Au-TiO2 catalyst was found to be very active for HMF oxidation; however, this system deactivated very fast. For this reason, we prepared bimetallic gold-copper nanoparticles and an increase in the catalytic activity was observed together with an increase in catalyst stability. In order to optimise the interaction of the metal active phase with the support, Au and AuCu nanoparticles were supported onto CeO2. Au-CeO2 catalyst was found to be more active than the bimetallic one, leading to the conclusion that in this case the most important feature is the interaction between gold and the support. Catalyst pre-treatments (calcination and washing) were carried out to maximise the contact between the metal and the oxide and an increase in the FDCA production could be observed. The presence of ceria defective sites was crucial for FDCA formation. Mesoporous cerium oxide was synthesised with the hard template method and was used as support for Au nanoparticles to promote the catalytic activity. In order to study the role of active phase in HMF oxidation, PdAu nanoparticles were supported onto TiO2. Au and Pd monometallic catalysts were very active in the formation of HMFCA (5-hydroxymethyl-2-furan carboxylic acid), but Pd was not able to convert it, leading to a low FDCA yield. The calcination of PdAu catalysts led to Pd segregation on the particles surface, which changed the reaction pathway and included an important contribution of the Cannizzaro reaction. PVP protected PdAu nanoparticles, synthesised with different morphologies (core-shell and alloyed structure), confirmed the presence of a different reaction mechanism when the metal surface composition changes.

Abstract
Tipologia del documento
Tesi di dottorato
Autore
Lolli, Alice
Supervisore
Co-supervisore
Dottorato di ricerca
Scuola di dottorato
Scienze chimiche
Ciclo
27
Coordinatore
Settore disciplinare
Settore concorsuale
Parole chiave
selective oxidation of HMF, 5-hydroxymethylfurfural, 5-hydroxymethyl-2-furfural, FDCA, 2,5-furandicarboxylic acid, Cannizzaro reaction, gold-copper catalysts, CeO2, TiO2, Pd-Au nanoparticles, preformed nanoparticles
URN:NBN
DOI
10.6092/unibo/amsdottorato/6924
Data di discussione
29 Aprile 2015
URI

Altri metadati

Statistica sui download

Gestione del documento: Visualizza la tesi

^