Effect of Phosphorus-to-Nickel Ratio on the Performance of Nickel-Based Catalysts in Hydroprocessing of Bisphenol A

This study investigates the effect of the P/Ni molar ratio on the activity of nickel-based catalysts synthesized in situ during the hydrodeoxygenation of bisphenol A (BPA). BPA conversion is near-complete regardless of the P/Ni ratio, whereas the degree of deoxygenation depends significantly on the composition of the catalyst formed. The in situ synthesized catalysts were characterized by X-ray diffraction (XRD). Introducing phosphorus increased the degree of deoxygenation from 17 to 57% (at P/Ni = 2). However, further increasing the P/Ni ratio to 3–4 reduced the deoxygenation degree to 7–17% due to the formation of phosphate phases and excess phosphorus on the catalyst surface. Catalysts containing a Ni12P5 phosphide phase exhibited the greatest activity in hydrodeoxygenation and hydrogenation. These results demonstrate the key role of phosphide composition and phosphate phases in catalytic activity.