Self-tuned properties of CuZnO catalysts for hydroxymethylfurfural hydrodeoxygenation towards dimethylfuran production†
5-Hydroxymethylfurfural (HMF) is a very valuable platform molecule obtained from biomass. It can be catalytically transformed to many industrially relevant products of both oxidation and reduction reactions. In this work, we showed that robust CuZnO can be an efficient, self-tuned catalyst for 2,5-dimethylfuran (DMF) (biofuel additive) synthesis. We showed that CuZnO catalysts can be further activated in the reaction environment and this process depends strongly on the initial catalyst properties and therefore on the catalyst preparation method. Smaller copper particles are more active but more prone to carbon deposit formation. Based on activity tests and extensive characterization, we have concluded that both Cun+ and Cu0 sites are necessary for high HMF conversion. While these two sites favor high conversion and high 2,5-bishydroxymethylfuran (BHMF) yield, the in situ formation of Lewis acid sites is proposed to be necessary for achieving a high DMF yield.