abstract
Aiming at the valorisation of furfural (Fur) via sustainable routes based on process intensification and heterogeneous catalysis, the one-pot conversion of this renewable platform chemical to useful bio-products, namely furfuryl alkyl ethers (FEs), levulinate esters (LEs), levulinic acid (LA), angelica lactones (AnLs) and gamma-valerolactone (GVL), was investigated using a single heterogeneous catalyst, in 2-butanol, at 120 degrees C. Various chemical reactions are involved in this process, which requires catalysts with active sites for acid and reduction chemistry. For this purpose, it was explored for the first time the catalytic potentialities of modified versions of zeolite beta containing Al and Sn sites prepared from commercially available nanocrystalline zeolite beta via post-synthesis partial dealumination followed by solid-state ion-exchange. The post-synthesis conditions influenced considerably the catalytic performances of these types of materials. The best-performing catalyst was (Sn)(SSIE)-beta1 with Si/(Al + Sn) = 19 (Sn/Al = 27), which led to total yield of bio-products of 83% at 86% Fur conversion, and exhibited steady catalytic performance for six consecutive runs. A systematic catalytic study using the prepared catalysts with different bio-products as substrates, together with the molecular level and microstructural characterisation of the materials, helped understand the effects of different material properties on the specific reaction pathways in the overall system. These studies led to mechanistic insights into the reaction network of Fur to the bio-products in alcohol media, upon which a kinetic model was developed for the first time. The superior performance of (Sn)(SSIE)-beta1 in various steps was related to the dealumination degree, dispersion and amount of Sn-sites, and acid properties. (C) 2015 Elsevier Inc. All rights reserved.
keywords
MEERWEIN-PONNDORF-VERLEY; BAEYER-VILLIGER OXIDATION; FLUIDIZED-BED REACTOR; LEWIS-ACID CATALYSTS; GAMMA-VALEROLACTONE; TRANSFER HYDROGENATION; LEVULINIC ACID; ETHYL LEVULINATE; SN-BETA; AQUEOUS-PHASE
subject category
Chemistry; Engineering
authors
Antunes, MM; Lima, S; Neves, P; Magalhaes, AL; Fazio, E; Fernandes, A; Neri, F; Silva, CM; Rocha, SM; Eiro, MFR; Pillinger, M; Urakawa, A; Valente, AA
our authors
Ana Luísa Carvalho Magalhães
Post-doc Fellowship
Anabela Tavares Aguiar Valente
Principal Researcher
Carlos Manuel Silva
Associate Professor
Maria Margarida Feitor Pintão Moreno Antunes
Junior Researcher
Martyn Pillinger
Principal Researcher
Patrícia dos Santos Neves
Assistant Researcheracknowledgements
This work was developed in the scope of the project CICECO-Aveiro Institute of Materials (Ref. FCT UID/CTM/50011/2013) and QOPNA research Unit (FCT UID/QUI/00062/2013), financed by national funds through the FCT/MEC and when applicable co-financed by FEDER under the PT2020 Partnership Agreement. The FCT and the European Union are acknowledged for grants to M.M.A. (SFRH/BPD/89068/2012), P.N. (SFRH/BPD/73540/2010), A.L.M. (SFRH/BPD/95393/2013) and A.F. (SFRH/BPD/91397/2012), cofunded by MCTES and the ESF through the program POPH of QREN. The authors wish to thank Antonio J.S. Fernandes (I3 N, Department of Physics, University of Aveiro) for assistance with the UV-Raman data measurements; and Luis Mafra and Mariana Sardo for helpful discussions of NMR characterisation. SL and AU thank MINECO for support through Severo Ochoa Excellence Accreditation 2014-2018 (SEV-2013-0319).