Effect of the physicochemical properties of bimetallic Ni-Cu catalysts for hydrogenation/hydrogenolysis of HMF varying the synthesis method

Abstract

The evident necessity to transition away from a reliance on fossil resources implies the need to produce high-value-added chemicals from non-conventional sources, such as lignocellulosic biomass. The cellulosic fraction of this resource can be converted into 5-hydroxymethylfurfural (HMF), which can be further transformed to 2,5-bis(hydroxymethyl)furan (BHMF), a polymeric precursor, or 2,5-dimethylfuran (DMF), serving as a substitute or additive of conventional gasoline. This work investigates the effect of the synthesis method of the Ni-Cu/ZrO2 catalyst on the conversion of HMF to BHMF or DMF. The preparation process exerts influence on the dispersion of metals, the acidity of the catalyst, and the interaction of Ni-Cu. Consequently, product selectivity varied depending on the catalyst preparation method, with BHMF being the primary product when the catalyst was prepared through wet impregnation and DMF when precipitation was the chosen synthesis method. Concretely, a BHMF yield of 60% yield was achieved at 150 °C with the impregnated catalyst, while a 65% yield was obtained for DMF when employing the precipitation-prepared catalyst. Furthermore, a noticeable effect of the temperature on product selectivity was also detected.