Zeolitic framework Sn boosts the 2,5-dimethylfuran selectivity for the hydrodeoxygenation of 5-hydroxymethylfurfural over Co/Sn-Beta catalyst

Non-noble metal catalysts possess great potential for practical applications concerning selective hydrodeoxygenation of biomass-derived 5-hydroxymethylfurfural (HMF) to 2,5-dimethylfuran (DMF), whose rational design, catalytic mechanism, and precisely chemical control of targeted product DMF selectivity are highly desired but still significantly challengeable research topics. Herein, non-noble Co was loaded on the support of Sn-Beta metallosilicate zeolites to establish Co/Sn-Beta composite catalyst for this oriented conversion. The Co and Sn contents in Co/Sn-Beta were closely associated with the catalytic performance. Under the present reaction conditions and with the suitable metal contents, metallic Co and framework Sn mainly modulated the HMF conversion and DMF selectivity, respectively. The framework Sn in Sn-Beta zeolites enhanced the DMF selectivity by increasing the adsorption capacity and conversion of the intermediate product 2,5-bis(hydroxymethyl)furan. Under the optimal conditions, HMF conversion and DMF selectivity achieved 100 % and >99.9%, respectively, confirming that Co/Sn-Beta was a robust catalyst for HMF hydrodeoxygenation. Finally, the catalytic mechanism was also put forward, obeying a parallel and tandem reaction pathway. This work aims to provide some guidance for designing metallosilicate zeolite supported non-noble metal catalyst from the view of support-enhanced effect in order to regulate the product selectivity during biomass catalytic conversions.