Twenty-two tons of catalyst was used in the 130kt/a industrial PX device at Sinopec Qilu Company for removing trace olefins from aromatics. The result showed it had an effective running time about 3 times as long as that of the commercial clay. The reaction mechanism was explored and it indicated that the weak L acid was the main reason for the enhancement of the catalyst activity. In addition, the process of the olefins reacted with the aromatics via the carbonium ion mechanism can be generalized by the alkylation reaction. (C) 2012 Elsevier B.V. All rights reserved.