Selective hydrogenation of bio-based 5-hydroxymethyl furfural to 2,5-dimethylfuran over magnetically separable Fe-Pd/C bimetallic nanocatalyst

Abstract

There is an ever increasing need to innovate and provide alternative energy sources to reduce the overdependence on conventional fossil fuels. 2, 5-Dimethylfuran (DMF), a bio-based chemical, has gained a lot of attention due to its potential application as a biofuel additive and is synthesized through hydrogenation of 5-hydroxymethylfurfural (HMF). Bimetallic nano-catalysts have gained importance in recent years due to their excellent selectivity and activity. In this paper, a magnetically separable Fe-Pd/C bimetallic nano-catalyst was developed which not only showed excellent selectivity to DMF but also helped reduce the noble metal consumption, thereby making the catalyst cheaper. Using XPS, XRD and TPR characterizarion techniques, the Fe-Pd/C catalyst was found to exist as bimetallic containing a partially oxidized Fe and reduced Pd atoms. It exhibited 85% selectivity towards DMF with 100% conversion of HMF. The reaction was conducted in a liquid-acid-free environment, thus making the process environmental friendly. The oxidized Fe imparts magnetic properties to the catalyst making it easy to recover. The catalyst was found to be robust and showed excellent activity on repeated use. Overall a highly efficient, economic and green process for DMF synthesis was developed based on biomass as feedstock.