Relationship between the structure and activity of ruthenium catalysts in the catalytic ozonation of dimethyl phthalate

Ruthenium catalysts on various activated carbon (AC) supports were prepared using conventional calcination and microwave irradiation.Their activity in the catalytic ozonation of dimethyl phthalate was studied.The relationship between the structure and activity was investigated.All the supports and catalysts increased total organic carbon removal.The activity order was Ru/coal-AC > nutshell-AC > Ru/nutshell-AC > Ru/coconut-AC ≈ coal-AC > coconut-AC.The supported Ru particles diffused into the macropores, which increased mass transfer resistance in catalytic ozonation and decreased the probability that the reactants can contact the active phase on the interior surface.This was one reason why the activity of nutshell-AC and Ru/nutshell-AC was lower than that of Ru/coal-AC.A difference in Ru dispersion on the surface of the catalyst also caused the activity difference.The active phase on the surface of nutshell-AC can be changed by microwave irradiation, which caused Ru/nutshell-AC to even be less active than the corresponding support.As compared to the use of conventional calcination, the use of microwave irradiation enhanced the metal dispersion and catalytic activity of Ru/coal-AC.