Synthesis of catalysts by pyrolysis of Cu-chitosan complexes and their evaluation in the hydrogenation of furfural to value-added products

Abstract

• Cu 2+ -species have been complexed with chitosan in acid medium. • Cu 2+ -chitosan composites have been pyrolyzed to obtain Cu 0 -carbon catalysts. • Cu 0 -carbon catalysts have been tested in the furfural hydrogenation successfully. • All catalysts tend to form furfuryl alcohol as main product. • The deposition of furfural and furfuryl alcohol causes a progressive blockage of the active sites. Chitosan has been used in the synthesis of catalysts for the furfural hydrogenation to obtain furfuryl alcohol. Cu-based catalysts supported on a carbonaceous matrix have been synthesized by complexation of Cu 2+ species with the free electron pairs of the amino groups of chitosan under acid conditions, dried and subsequent pyrolysis. The catalytic behavior shows how the most active catalyst is Chi30Cu (30 wt% Cu), reaching a conversion close to 65% after 5 h at 190 °C. In all cases, a progressive deactivation is observed as a consequence of the adsorption of furfural and furfuryl alcohol on the support. With regard to the obtained products, these catalysts are selective to furfuryl alcohol, so these catalysts are environmentally sustainable and have great potential to be used in the synthesis of furfuryl alcohol as an alternative to copper chromite, which is highly toxic due to the presence of Cr species.