The incorporation of bismuth in fluorinated carbon covered alumina (FCCA) supported Pd catalysts has shown to increase significantly the catalytic activity in the hydrodechlori nation of CCl2F2 and CH2F2 selectivity. During the preparation of FCCA, the formation of alpha-AlF3 and carbon coverage on alumina has helped in creating the extra acidity and in minimizing the support active component interaction respectively. XRD data shown the formation of interacted species, BiPd3 between Pd and Bi. XPS analysis shows that in Pd/FCCA spent catalyst, Pd is transformed into Pd halides whereas in the Bi-Pd/FCCA spent catalysts Pd maintains its metallic state even in presence of corrosive reaction atmosphere. Bi-promoted catalysts exhibited higher selectivity towards CH2F2 at Bi/Pd = 0.5 and good thermal stability in the hydrodechlorination of CCl2F2. (C) 2003 Elsevier B.V. All rights reserved.