摘要
A cobalt-based hydrotalcite-like compound was prepared using a constant-pH coprecipitation method.Cobalt-transition metal oxides(Co2XA10,X=Co,Mg,Ca and Ni)were investigated for the deep catalytic oxidation of o-chlorophenol as a typical heteroatom contaminant containing chlorine atoms.The partial substitution of Co by Mg,Ca or Ni in the mixed oxide can promote the catalytic oxidation of o-chlorophenol.The Co2MgA10 catalyst presented the best catalytic activity,and could maintain 90%o-chlorophenol conversion at 167.1℃,compared only 27%conversion for the Co3A10 catalyst.The results demonstrated that the high activity could be attributed to its increased low-temperature reducibility,rich active oxygen species and excellent oxygen mobility.In the existence of acid and base sites,catalysts with strong basicity also showed preferred activity.The organic by-products generated during the o-chlorophenol catalytic oxidation over Co2MgAlO catalyst included carbon tetrachloride,trichloroethylene,2,4-dichlorophenol,and 2,6-dichloro-p-benzoquinon,et al.This work provides a facile method for the preparation of Co-based composite oxide catalysts,which represent promising candidates for typical chlorinated and oxygenated volatile organic compounds.
基金
This work is financially supported by the National Natural Science Foundation of China(Grant Nos.21677160 and 21477149)
Beijing Municipal Science&Technology Commission(Nos.Z181100000118003 and Z 181100005418011).