Synthesis and characterization of bimetallic catalysts Pd-Ru and Pt-Ru supported on γ-alumina and zeolite FAU for the catalytic transformation of HMF

It is well known the effects and limitations of the use of fossil fuels, for that reason is necessary to establish alternative sources of energy. The 5-hydroxymethylfurfural (HMF) is a chemical compound that can be obtained from the carbohydrates present in the biomass. Is a key compound for the obtaining of several valuable chemicals, many of them have a promising application as biofuels. In the present work, Pd-Ru and Pt-Ru bimetallic catalysts with low metal content (0.5%) supported on commercial gamma-Al2O3 and FAU zeolite prepared by hydrothermal method, were synthesized and characterized to transform HMF into valuable chemicals under mild reaction conditions. Two crystallographic phases were found to coexist in the zeolite synthesized as support, the FAU phase prevailing over the LTA when calcined at 550 degrees C. The system studied with formic acid as hydrogen donor, under mild reaction conditions, showed a partial hydrogenation of HMF molecule evidenced in the 5-MF and 2,5-DMF formation. Also, a partial oxidation and esterification is happening for the formation of 2,5-DFF and 5-A-2-F, respectively. The catalysts supported on FAU showed better conversion of HMF that catalysts supported on gamma-Al2O3. Although all metals showed catalytic activity by separed, Pd-Ru combination was more selective to produce 5-MF, 2,5-DMF and 2,5-DFF than Pt-Ru combination, and showed production of valuable furan derivatives even in their second and thir use. Pd-Ru/FAU catalyst formed a PdRu alloy phase, which can be related to its better catalytic performance.