p-Tolunitrile has been efficiently synthesized by liquid phase ammoxidation of p-xylene over silica-supported Co-Mn-Mg-Ni-O/SiO
2
catalyst without solvent for the first time in one-pot procedure.The optimum reaction conditions were that: the composition of catalyst n(Co)∶n(Mn)∶n(Mg)∶n(Ni)=(1∶1.012)∶1.224∶0.081;the mass fraction of catalyst is 3.3%;the mole ratio of air to ammonia n(air)∶(n(NH
3
))=6∶1;the reaction temperature is 190 ℃;the pressure is 0.5 MPa.Under the optimum conditions