Natural wood templated polyaniline catalysts for energy efficient saccharide-HMF conversion

Wood templated carbon / polyaniline (PANI) hybrid catalyst was successfully synthesized through microwave-assisted fructose conversion reactions. The surface property of carbonized wood was modified via a series of oxidation and carbonization processes to improve the anchoring of polyaniline on the surface. Various characteriza- tion techniques were used to study the microstructure evolution and surface composition of carbon frame as well as the polyaniline morphology and composition. By coupling air oxidation and chemical-treatment of carbon support, the PA- NI loading significantly enhanced from about 1 wt% to 8 wt%. The results showed that the presence of the hydroxyl groups on carbon support not only promoted the PANI deposition on the carbon frame but also enhanced its microwave absorption ability in the aqueous media. In the fructose dehydration reaction, the hybrid showed better microwave ab- sorption and consequently about 36% higher reaction temperature. The hybrid catalyst achieved 70% 5-hydroxymethyl- furfural yield within 30-min reaction. In addition, the bulk catalyst can be easily recycled and conveniently reactivated for multiple reaction cycles.