Abstract: In view of the problems of large amount of catalyst used and waste residue with lots of product and pollution in diphenylamine alkylation process, the modification of the clay atalyst was performed, the operation conditions were determined. By use of the modified catalyst, the products with similar physicochemical and antioxidant performance to industrial product are obtained. The results show that the improved catalyst can meet the need of existing process and reduce the usage amount of catalyst, resulting in less pollution, higher yield and benefit.

Key words: antioxidant, alkylated diphenylamine, catalyst