Stability and activity of Pt and Ni catalysts for hydrodeoxygenation in supercritical water

We determined the stability, activity, and selectivity of Pt/C, Ni/SiO ₂Al₂O₃, Raney Ni 2800, and Raney NiCu for the hydrodeoxygenation (HDO) of o-cresol in supercritical water at 380 °C. We also demonstrate the feasibility of using a renewable chemical, formic acid, for the in situ production of the H₂ needed for HDO. Pt/C, Raney Ni, and Raney NiCu were stable in supercritical water, but only Pt/C and Raney NiCu were selective to deoxygenated products. The Raney NiCu catalyst provided a 3.4-fold increase in yield of deoxygenated products when compared with the Raney Ni catalyst by decreasing the CC bond hydrogenolysis activity. The Raney NiCu catalyst was stable throughout the 24 h time on stream that was examined and appears to be a promising catalyst for further study and optimization.