how to convert phenol to benzene with mechanism

Its a one step process.
Distillation of phenol in contact with powdered zinc will in fact yield benzene and zinc oxide. 3 down vote accepted

Zn shows an oxidation state of +2.

The phenol gets converted into phenoxide ion and proton thus released accepts an electron from Zn forming H radical.

Also because of the heating there is homolytic fission of C of phenyl ring and O-

The O- thus formed accepts an electron from Zn and forms oxide ion.

In this way zinc forms zinc oxide and phenyl radical thus produced forms a bond with H radical.