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 -valerolactone (GVL), was investigated using a single heterogeneous catalyst, in 2-butanol, at 120 ºC. Various chemical 2 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 nanocrystaline 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=27.6), 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.

Ordered porous silicates of the type TUD-1 and zeolite beta possessing zirconium and aluminium sites were evaluated as eco-friendly heterogeneous, multifunctional catalysts for the integrated reduction-acid conversion of furfural (Fur, industrially produced from hemicellulosic components of biomass) to useful bio-products, namely, furfuryl alcohol (FA), alkyl furfuryl ethers (FEs), alkyl levulinate esters (LEs), levulinic acid (LA), angelica lactones (AnLs), and γ-valerolactone (GVL); the bio-products spectrum was obtained by GC × GC-ToFMS. Carrying out the one-pot conversion of Fur to bioproducts using a multifunctional catalyst is challenging since various reactions are involved and it is difficult to control all of these to meet high reaction efficiencies and selectivities. Aiming at designing improved multifunctional catalysts for this reaction system, the TUD-1 and zeolite beta type silicates possessing zirconium and aluminium sites in different ratios were prepared and characterised on microstructural and molecular levels. Systematic characterisation, catalytic testing using 2-butanol as dual functional solvent-H-donor, and kinetic modelling studies were performed using the Zr,Al-containing micro-and mesoporous materials. Different steps of the overall reaction of Fur were studied separately starting from intermediate products using the same materials, which helped understand the influence of the material properties on 2 reactivity of intermediates and reaction selectivity. Zr-sites of the silicate catalysts were essential for effectively initialising the overall process (reduction of Fur to FA), and for the reduction of LEs to GVL; the co-presence of Al-sites promoted acid-catalysed steps (FA to FEs, LEs, AnLs, LA). The good stability of the catalysts was verified by catalytic and characterisation studies of the spent catalysts.

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This work comprises two main purposes: to present the largest database of tracer diffusion coefficients ever published, comprehending 5279 experimental points and 296 binary systems, and provide the necessary Lennard-Jones diameter and energy, and the interaction parameter of the Liu−Silva−Macedo correlation (TLSMd), since it affords reliable and very good results for all systems studied (the global deviation found was 3.89%). For comparison, the well-known equations of Dymond−Hildebrand−Batschinsky, Zhu and co-workers, and Tyn−Calus have been adopted.