Investigating hydrodeoxygenation of furfural for 2-methylfuran production over Cu-Mo/CoOx catalyst: Influence of Mo promoter

Catalytic conversion of furfural (FF) into 2-methylfuran (2-MF) has received great attention, in which the control of catalytic selectivity plays a crucial issue. The design of efficient catalysts based on non-noble metals is still a huge challenge for this transformation. Herein, transition metal oxide CoOx supported Cu catalysts have been prepared via a simple sol–gel route and applied in this transformation. A significantly enhanced 2-MF selectivity have been achieved when Mo was used as an additive during preparation. Under mild conditions (180 °C and 2 MPa H2), the conversion of FF exceeds 99% and 2-MF yield was up to 92% over the Cu-Mo/CoOx with the molar ratio of Cu/Mo is 3. Characterization results demonstrated that the addition of Mo not only accelerated the formation of CuCo alloy in the catalyst, but also enhanced the electropositivity of Coδ+ due to the electron transfer from Co to Mo, which then affected the adsorption mode of C = O from η1-(O) to η2-(C, O). Consequently, this adsorption configuration and abundant Lewis acid sites on Cu-Mo/CoOx facilitates the C-O cleavage, giving rise to the production of 2-MF. In addition, Cu-Mo/CoOx also exhibits good stability during the recycle experiment.