Support Induced Control of Surface Composition in Cu–Ni/TiO₂ Catalysts Enables High Yield Co-Conversion of HMF and Furfural to Methylated Furans

5-(Hydroxymethyl)furfural (HMF) and furfural (FF) have been identified as valuable biomass-derived fuel precursors suitable for catalytic hydrodeoxygenation (HDO) to produce high octane fuel additives such dimethyl furan (DMF) and methyl furan (MF), respectively. In order to realize economically viable production of DMF and MF from biomass, catalytic processes with high yields, low catalyst costs, and process simplicity are needed. Here, we demonstrate simultaneous coprocessing of HMF and FF over Cu–Ni/TiO2 catalysts, achieving 87.5% yield of DMF from HMF and 88.5% yield of MF from FF in a one pot reaction. The Cu–Ni/TiO2 catalyst exhibited improved stability and regeneration compared to Cu/TiO2 and Cu/Al2O3 catalysts for FF HDO, with a ∼7% loss in FF conversion over four sequential recycles, compared to a ∼50% loss in FF conversion for Cu/Al2O3 and a ∼30% loss in conversion for Cu/TiO2. Characterization of the Cu–Ni/TiO2 catalyst by X-ray photoelectron spectroscopy, scanning transmission electron microscopy, and H2–temperature-programmed reduction and comparison to monometallic Cu and Ni on Al2O3 and TiO2 and bimetallic Cu–Ni/Al2O3 catalysts suggest that the unique reactivity and stability of Cu–Ni/TiO2 derives from support-induced metal segregation in which Cu is selectively enriched at the catalyst surface, while Ni is enriched at the TiO2 interface. These results demonstrate that Cu–Ni/TiO2 catalysts promise to be a system capable of integrating directly with a combined HMF and FF product stream from biomass processing to realize lower cost production of liquid fuels from biomass.