Renewable bio-based routes to gamma-valerolactone in the presence of hafnium nanocrystalline or hierarchical microcrystalline zeotype catalysts

abstract

Different renewable bio-based routes leading to the versatile bioproduct gamma-valerolactone (GVL) were studied in integrated fashions, starting from furfural (Fur), alpha-angelica lactone (AnL) and levulinic acid (LA), in the presence of multifunctional hafnium-containing catalysts, in alcohol media. These routes involved acid and reduction reactions for which multifunctional catalysts were prepared via top-down strategies, namely the nanocatalyst Hf-deAlBeta-n and the hierarchical (intracrystalline micro/mesopores) microcrystalline material Hf-WdeSAlBeta-m. Mechanistic and kinetic modelling studies, molecular-level investigations by solid-state spectroscopic characterization, and catalyst stability studies led to assessments about the catalytic roles and potentialities of the prepared materials for GVL production. The influences of the catalytic reaction conditions and type of transition metal in the catalysts were studied. The best-performing catalyst was the hierarchical zeotype Hf-WdeSAlBeta-m (GVL yields of up to 99% from LA, 91% from AnL, and 73% from Fur, at 180 degrees C), which correlated with its enhanced acidity and mesoporosity. To the best of our knowledge, this is the first reported hafnium-containing BEA zeotype possessing an intracrystalline hierarchical pore system, and the results highlighted the catalytic potentialities of these types of materials for the integrated production of GVL. (C) 2021 Elsevier Inc. All rights reserved.

keywords

MEERWEIN-PONNDORF-VERLEY; METAL-ORGANIC FRAMEWORKS; ONE-POT CONVERSION; LEWIS-ACID SITES; AL-BETA ZEOLITE; LEVULINIC ACID; TRANSFER-HYDROGENATION; LIGNOCELLULOSIC BIOMASS; HETEROGENEOUS CATALYST; METHYL LEVULINATE

subject category

Chemistry; Engineering

authors

Antunes, MM; Silva, AF; Fernandes, A; Pillinger, M; Ribeiro, F; Valente, AA

Groups

G1 - Porous Materials and Nanosystems
G4 - Renewable Materials and Circular Economy

Projects

CICECO - Aveiro Institute of Materials (UIDB/50011/2020)

CICECO - Aveiro Institute of Materials (UIDP/50011/2020)

Conversao catalitica de olefinas derivadas da biomassa (BiOle_AcidOxCat)

Rede Nacional de Ressonância Magnética Nuclear (PTNMR)

acknowledgements

This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020 & UIDP/50011/2020, financed by national funds through the Por-tuguese Foundation for Science and Technology/MCTES. The posi-tions held by M.M.A. and A.F. were funded by national funds (OE) , through FCT, I.P., in the scope of the framework contract fore-seen in the numbers 4, 5 and 6 of article 23 of the Decree-Law 57/2016 of 29 August, changed by Law 57/2017 of 19 July. The position held by A.F.S. was funded by Project POCI-01-0145-FEDER-030075 (COMPETE 2020 Operational Thematic Program for Competitiveness and Internationalization) co-financed by national funds through the FCT/MCTES and the European Union through the European Regional Development Fund under the Por-tugal 2020 Partnership Agreement. The NMR spectrometer used is part of the National NMR Network (PTNMR) and is partially sup-ported by Infrastructure Project N degrees 022161 (co-financed by FEDER through COMPETE 2020, POCI and PORL and FCT through PIDDAC) . The authors are grateful to Dr Gonzalo Otero Irurueta from TEMA (University of Aveiro) for the helpful discussions of the XPS spec-troscopy results.