A range of catalysts consisting of zinc impregnated gamma-Al2O3 has been examined for the fluorination of chlorofluorocarbons. Addition of zinc to gamma-Al2O3 promotes steady state fluorination of CF2CICFCI2 (CFC-113) to 1,1,1,2-tetrafluoro-2,2-dichloroethane (CFC-114a). Zinc promotion of fluorination activity was maximised at 6.5 wt%. Temperature programmed reaction (TPR) studies on pre-fluorided catalysts show that CCI4 is fluorinated by a sequential mechanism, with CCI3F a primary product and CCl2F2 a secondary product. The addition of zinc to gamma-Al2O3 resulted in a low temperature feature in the TPR profile, and further analysis shows that there is a strong correlation between catalyst activity for CFC-113 fluorination and the concentration of fluorine associated with this low temperature feature. As the site population of the low temperature feature increases the apparent activation energy for the CFC-113 fluorination process decreases. Higher temperature HF pre-treatment resulted in a significant reduction of the population of this low temperature site compared to the standard conditions without pre-treatment, indicating that active fluorine consists of labile surface bonded H-F, rather than a metal fluoride such as AIF(3) or ZnF2. Based on experiments investigating highly dispersed zinc on an activated carbon support, zinc adjacent to an Al3+ ion is required for fluorination, since this allows adsorption of active HF in close proximity to a Lewis acid site, where the CFC can adsorb. Crown Copyright (C) 2018 Published by Elsevier Inc. All rights reserved.