Copper-Zinc Alloy Nanopowder: A Robust Precious-Metal-Free Catalyst for the Conversion of 5-Hydroxymethylfurfural

Noble-metal-free copper-zinc nanoalloy (<150nm) is found to be uniquely suited for the highly selective catalytic conversion of 5-hydroxymethylfurfural (HMF) to potential biofuels or chemical building blocks. Clean mixtures of 2,5-dimethylfuran (DMF) and 2,5-dimethyltetrahydrofuran (DMTHF) with combined product yields up to 97% were obtained at 200-220 degrees C using 20-30bar H-2. It is also possible to convert 10wt% HMF solutions in CPME, with an excellent DMF yield of 90%. Milder temperatures favor selective (95%) formation of 2,5-furandimethanol (FDM). The one-pot conversion of fructose to valuable furan-ethers was also explored. Recycling experiments for DMF production show remarkable catalyst stability. Transmission electron microscopy (TEM) characterization provides more insight into morphological changes of this intriguing class of materials during catalysis.