Hydrodeoxygenation of anisole to benzene over Fe2P catalyst by a direct deoxygenation pathway

Developing economically viable and highly selective hydrodeoxygenation (HDO) catalysts for C-O bond cleavage of lignin-derived aryl ethers is virtually important but still challenging. Herein, a novel monometallic Fe2P catalyst was synthesized by a two-stage phosphorization method under mild conditions, which showed high arene (benzene) selectivity of 96.7% among 'C' _'6' ^'+' products with the turnover frequency of 8.2 × 10-3 mol molCO-1 s-1 in the HDO of anisole at 200 oC and ambient hydrogen pressure. Characterization results revealed that the crystal structure of Fe2P catalyst was stable and no phosphorus loss in the reduction and reaction process. The kinetic results indicated that the coverage of anisole was higher than that of H2 on the Fe2P catalyst. The anisole temperature programmed surface reaction (anisole-TPSR) and density functional theory (DFT) calculations results identified the anisole HDO reaction mechanism was the direct cleavage of Caryl-O bond of anisole to form C6H5* and CH3O* without forming C6H5-OH-CH3 intermediate. These findings may contribute to understand the iron based phosphide and guide the catalyst design for the HDO of aryl ethers and related reactions.