Abstract:
Furfural (FAL) and 5-hydroxymethylfurfural (HMF) are important and sustainable platform chemicals. They
are produced from lignocellulose biomass and attract significant attention as precursors for producing
value-added chemicals and fuels. The selective conversion of these chemicals requires precise modulation
of reaction parameters, solvent, and catalyst. In this study, FAL is selectively reduced to furfuryl alcohol
(FOL), and HMF is selectively oxidized to 2,5-diformylfuran (DFF) over a Cu and Ru decorated copper
aluminophosphate (CuAlPO-5) catalyst. A high FAL conversion (99.5%) and FOL selectivity (99.6%) are
obtained in water under mild reaction conditions of 353 K and 1 MPa H2 pressure. On the other hand,
94.0% HMF conversion and 99.9% DFF selectivity are obtained at 1 atm O2 flow at 413 K. Both these
processes are efficiently conducted over Cu and Ru nanoparticles supported CuAlPO-5 at optimized Cu
and Ru contents and under different reaction conditions. The calculated activation energies for these
processes are 21.5 kJ mol−1 (for FAL hydrogenation) and 34.5 kJ mol−1 (for HMF oxidation). The
temperature-programmed reduction/oxidation (TPR/TPO) and adsorption results suggest the synergy
between Cu and Ru, resulting in higher catalytic activity. Systematic and precise modulation of active metal
contents and minimizing the Ru content in the Cu–Ru bimetallic catalyst system would be desirable from
the industrial and academic perspective, especially for achieving oxidation/reduction capabilities in biomass
conversion using a single catalyst
