HMF hydrogenolysis over carbon-supported Ni–Cu catalysts to produce hydrogenated biofuels

Abstract

Non-noble monometallic and bimetallic catalysts supported in biomass-derived carbon were tested in the 2,5-dimethylfuran (DMF) and 2,5-dimethyltetrahydrofuran (DMTHF) production from 5-hydroxymethylfurfural (HMF) hydrogenolysis using a fixed-bed continuous-flow reactor. These support and reaction system were selected in order to obtain a more sustainable catalyst development and to implement a continuous flow reaction system. The carbon-supported biomass-derived catalysts were compared with catalysts supported on commercial carbons, which were treated with acid to remove impurities. All the bimetallic catalysts exhibited high stability after 25 h-on stream, achieving DMF yields above 50% and complete HMF conversion. Biomass-derived carbon supported catalysts seems more selective toward DMF during the 8-9 h-on stream than commercial carbon supported ones. The good activity and stability of the bimetallic catalysts seems to be related to the synergistic effect between acid and metallic sites, exhibiting the most promising ones an excellent stability for 46 h on stream. Monometallic catalysts exhibited high yields, above 70%, at the beginning of the reaction. However, they suffer from partial deactivation, probably due to metal sintering. Finally, the obtained catalytic activities and selectivities toward target products are close to the reported ones for discontinuous systems, being an important aspect for its possible industrial application.