Highly selective bimetallic FeMoP catalyst for C–O bond cleavage of aryl ethers

We report the synthesis of an industrially applicable, non-sulfided bimetallic catalyst with remarkable selectivity to the hydrodeoxygenation of aryl ethers and phenol. Bimetallic FeMo phosphide catalysts have selectivities as high as ∼90% benzene and 10% cyclohexane at hydroprocessing temperatures (400 °C) and industrially low pressures (2.1 MPa H2) at near complete conversion (>99%). Similarly, the selectivities for the hydrodeoxygenation of anisole were 90% benzene, 4% toluene, and 6% cyclohexane at 92% conversion. Furthermore, this catalyst has the ability to cleave aryl ether bonds and specifically β-O-4 linkages with higher selectivities to aromatics compared to hydrocarbons, thus minimizing the use of expensive H2. The selectivity to aromatics from phenol was highly dependent on H2 pressure, where doubling the pressure to 4.2 MPa reduced the selectivity to benzene, while less substantial decreases were observed when anisole or a β-O-4 model compound was reacted. These high selectivities were attributed to the unique FeMo phosphide material, as catalytic studies with FeP, MoP, and the combination of FeP and MoP resulted in selectivities much lower than the FeMo phosphide material.