Fabrication of carbon-supported Al2O3 nanoparticles via spontaneous cross-linking to enhance selective hydrogenation of furfural

A dendritic carbon networks supporting Al 2 O 3 nanoparticles hybrid based on spontaneous cross-linking of alginate and Al 3+ was constructed, which demonstrated outstanding selective hydrogenation performance of furfural to furfuryl alcohol . Selective hydrogenation of furfural to furfuryl alcohol is a great challenge in the hydrogenation field due to thermodynamic preference for hydrogenation of C C over C O. Herein, a novel Al 2 O 3 /C-u hybrid catalyst, composed of N-modified dendritic carbon networks supporting Al 2 O 3 nanoparticles , was successfully prepared via carbonizing the freeze-dried gel from spontaneous cross-linking of alginate , Al 3+ and urea . The obtained carbon-supported Al 2 O 3 hybrid catalyst has a high ratio (31%) of Al species in pentahedral-coordinated state. The introduction of urea enhances the surface N content, the ratio of pyrrolic N, and specific surface area of catalyst, leading to improved adsorption capacity of C O and the accessibility of active sites. In the furfural hydrogenation reaction with isopropyl alcohol as hydrogen donor, Al 2 O 3 /C-u catalyst achieved a 90% conversion of furfural with 98.0% selectivity to furfuryl alcohol , outperforming that of commercial γ-Al 2 O 3 . Moreover, Al 2 O 3 /C-u demonstrates excellent catalytic stability in the recycling tests attributed to the synergistic effect of abundant weak Lewis acid sites and the anchoring effect of the carbon network on Al 2 O 3 nanoparticles. This work provides an innovative and facile strategy for fabrication of carbon-supported Al 2 O 3 hybrid catalysts with rich Al V species, serving as a high selective hydrogenation catalyst through MPV reaction route.