Hydroxylation of benzene with oxygen and hydrogen over catalysts containing Group VIII metals and heteropoly compounds

The vapor phase hydroxylation of benzene to phenol with a mixture of oxygen and hydrogen over silica supported bi-component catalysts containing Group VIII metals (M) and heteropoly compounds (HPC) was investigated. The productivity of the catalysts was ascertained for various metal and HPC combinations and a range of reaction conditions. The Pt–PMo12/SiO2 and Pd–PMo12/SiO2 catalysts of optimal composition provide up to 380 mol phenol/g-atom Pt or Pd/h. The observed catalysis appears to be associated with an interface between metal particles and those of the heteropoly compound, as illustrated by an HREM image of a Pt–PMo12/SiO2 sample.