Mechanisms of selective cleavage of C–O bonds in di-aryl ethers in aqueous phase

A route for cleaving the C–O aryl ether bonds of p-substituted H–, CH3–, and OH– diphenyl ethers has been explored over Ni/SiO2 catalyst at very mild conditions (393 K, 0.6 MPa). The C–O bond of diphenyl ether is cleaved by parallel hydrogenolysis and hydrolysis (hydrogenolysis combined with HO* addition) on Ni. The rates as a function of H2 pressure from 0 to 10 MPa indicate that the rate-determining step is the C–O bond cleavage on Ni surface....