(617ax) Development of Pt/Al2O3 Catalytic System for the Production of Furanic Compounds from Biomass Derived Itaconic Acid

The needs for the innovative production of platform materials are increased due to the limitation of fuels and the effort to retain the sustainable hydrocarbon sources for chemical products. Biomass-derived feedstocks could be converted to chemical products by the hydrogenation and dehydration processes and be used as platform chemicals [1]. Thus, biomass could be candidate for renewable feedstocks and fuels. Among the various platform chemicals, furanic compounds are widely used as organic solvents and biofuel precursors. Methyl-tetrahydrofuran (MTHF) is a commercially used solvent that is produced from renewable resources. Also, methyl-γ-butyrolactone (MGBL) is used as solvent and reactant for processes. In these reasons, the conversion from biomass to furanic compounds is challenging tasks for both scientific and industrial aspects. The furanic compounds production from biomass-derived itaconic acid (IA) was reported by Geilen et al.by using Ru based homogeneous catalyst [2]. Ru catalysts, ligands and additives were used for conversion of IA into furanic compounds. IA was converted into furanic compounds by successive hydrogenation and dehydration processes. However the application of heterogeneous catalysts has not been reported yet for the IA conversion into the furanic compounds. The heterogeneous catalytic process is usually easier to handle than homogeneous catalytic process and leads to a lower risk for the environment.

Thus, we introduced the heterogeneous metal catalysts for producing methyl-γ-butyrolactone (MGBL) and 3-methyltetrahydrofuran (3-MTHF) as target materials. Ruthenium, palladium, platinum and iridium metal loaded catalysts were synthesized by wetness impregnation method with γ-Al₂O₃ as support. The activity of the catalyst was measured in batch reactor using 1 g of the catalyst. The IA conversion was carried out in the liquid phase: 0.05 M of IA, 200 ml of 1,4-dioxane solvent and prepared catalyst were placed into the reactor. The reaction pressure was 140 bar H₂and the temperature was 260ºC and the mixture was stirred with 1000 rpm for 18 hours. In the hydrogenation and dehydration of IA to MGBL and 3-MTHF using synthesized catalyst, methylsuccinc acid (MSA) and methylsuccinic anhydride (MSAN) were produced as intermediate chemicals.

Among the synthesized metal catalysts, Pt catalyst (3 wt.% Pt/γ-Al₂O₃) achieved the highest activity on the conversion of IA into 3-MTHF. In order to increase the hydrogenation and dehydration of carbonyl groups (C=O bond) in MSAN and MGBL, we further applied different kinds of Pt metal precursors to the Pt/γ-Al₂O₃ catalysts. It is well known that precursors of metal influence the properties of catalyst, which could promote the catalytic activity [3]. Thus, we introduced two kinds of Pt precursors, Pt(NH₃)₄(NO₃)₂ and H₂PtCl₆ on γ-Al₂O₃. In the case of chlorided catalyst (H₂PtCl₆), the chlorine remained after both calcination and reduction pretreatments. Also in this case, the lower 3-MTHF selectivities were exhibited than the case of chloride free catalyst (Pt(NH₃)₄(NO₃)₂) in all reduction temperature. These differences resulted from the differences of acidity and the amounts of H₂adsorbed on catalyst surface [4].

As a result, the highest 3-MTHF selectivity (44.1%) was obtained in the Pt catalyst prepared using Pt(NH₃)₄(NO₃)₂ precursor reduced at 400^oC. The remain chlorine decreased the catalytic activity, and the catalyst based on Pt(NH₃)₄(NO₃)₂ showed the highest activity on the hydrogenation and dehydration of carbonyl C=O bond in the MGBL. The additional characterization of catalyst will be performed and discussed. In the production of the chemicals from biomass-derived materials, these catalysts would be used for the active and energy efficient way for selective chemical production.

References

1. J.N. Chheda et al., Catal. Today, 123 (2007) 59
2. Frank M. A. Geilen et al., Angew. Chem., 122 (2010) 5642
3. M. Consonni et al., J. Catal., 188 (1999) 165
4. M. Paulis et al., J. Catal., 199 (2001) 30