Aqueous Phase Hydrodeoxygenation of Phenol on Hβ Zeolite Supported NiCo Alloy Catalysts

Zeolites (Hβ, HZSM-5 and HM), TiO₂ and ZrO₂ supported NiCo alloy catalysts were tested for the hydrodeoxygenation of phenol in aqueous phase. It has been found that the catalyst acidity remarkably influences the catalyst activity and the product distribution. Zeolites supported catalysts give much higher yield of the deoxygenated products (mainly benzene and cyclohexane) than NiCo/TiO₂ and NiCo/ZrO₂, where cyclohexanol and cyclohexanone are dominating. Associated with NH₃-TPD, we suggest that the catalyst acidity promotes the hydrodeoxygenation. Hβ zeolite supported NiCo alloy is more active than others, attributed to its higher metal dispersion and more acid sites. Therein, the Hβ zeolite calcined at 750 ^oC has moderate acidity, and its supported NiCo alloy catalyst (NiCo/HB-750) shows the best performance. Under a suitable reaction condition, the phenol conversion and the total yield of deoxygenated products reaches 96.8% and 94.5% on NiCo/HB-750, respectively.