Upgrading of diols by gas-phase dehydrogenation and dehydration reactions on bifunctional Cu-based oxides

摘要: Biomass-derived short-chain polyols can be transformed into valuable oxygenates used as building blocks. The gas phase conversion of a model molecule 1,3-diols (1,3-butanediol), was studied on bifunctional Cu–Mg, Cu–Al and Cu–Mg–Al mixed oxide catalysts that exhibit surface Cu0 particles acid–base properties. A series ZCuMgAl (Z = 0.3–61.2 wt.% Cu, Mg/Al 1.5 molar ratio) prepared by coprecipitation thoroughly characterized several techniques such BET area, TPR-N2O chemisorption, XRD TPD CO2. promote the upgrading diols dehydrogenation and/or dehydration reactions proceeding at reaction rates depend copper content (Z). overall activity increases linearly with amount species thereby confirming participation metallic sites in rate-limiting steps. Besides, favor pathway toward 1,3-butanediol dehydrogenation. Thus, dehydrogenation/dehydration selectivity ratio Z result enhanced exposed particles. 8 have higher yield multifunctional C4 hydroxyketones and, to lesser extent, unsaturated alcohols ketones. strongly basic Cu–Mg catalyst promotes C–C bond cleavage giving short carbon chain low rates; an acidic converts diol saturated ketones olefins.