The performance of a hybrid Sil-1/nanostructured anatase TiO2 membrane-catalyst and a catalytic titanium silicalite-1 (TS-1) membrane was evaluated for gas-phase photocatalytic oxidation (PCO) of trichloroethylene. The membrane-catalyst outperformed the catalytic plate coated with a similar amount of nanostructured TiO2 catalyst. However, the activity of the catalytic TS-membrane for PCO is low due to the insufficient number of active titanium sites in the TS-1 zeolite. (C) 2003 Elsevier Science Ltd. All rights reserved.