Hydrogenolysis and hydrocracking of the carbon-oxygen bond I. Hydrocracking of some simple aromatic O-compounds

Treatment of phenol, o-cresol, anisole, and guaiacol on a Ni-Mo/SiO2-Al2O3 hydrocracking catalyst is reported. The experiments were carried out in a fixed bed reactor at 250–350 °C, 5 MPa hydrogen pressure, and LHSV 0.5-2.5 h−1. Phenol and o-cresol were found to be relatively stable under the reaction conditions studied. Anisole and guaiacol reacted readily through cleavage of the alkyl-oxygen bond. Phenol, o-cresol, and 2,6-dimethylphenol were obtained as the main products from anisole. Guaiacol reacted first to pyrocatechol, which was the main product at 250–275 °C. At higher temperatures formation of phenol dominated, o- and m-cresol were formed in approximately equal amounts. The formation of hydrocarbons was minor in the case of guaiacol but from anisole appreciable amounts of cyclic C6-C7 hydrocarbons were obtained at 325–350 °C. The stability of the catalyst is described and tentative reaction mechanisms are discussed.