Recently, perfluoro compounds (PFCs) have been widely used in a variety of industrial, commercial, and consumer applications. In Taiwan, over 330 tons per year (TPY) of PFCs are extensively used for etching silicon wafers or clean chambers in chemical vapor deposition processes. Thus, the main objectives were to mineralize PFCs using oxalates, ZSM-5/Y/Beta/SBA-15 zeolites, and MOFs. Morphological observations, crystallinity, fine structures, oxidation states of products were also investigated with FE-SEM/EDS, TEM, XRD, FTIR, XPS or EXAFS/XANES techniques. Experimentally, they may also have effective destruction of PFCs by the rapidly capture of F atoms with subsequent nucleation/mineralization of salts under 573-673 K in few minutes. The morphologies of oxalates were irregular shape of inorganic powders with the particle sizes of 30-50 nm. The XRD patterns of oxalates samples showed are all crystalline structures. FTIR and EDS data also showed that PFCs may be mineralized completely by oxalates was decomposed to form salts, carbon, sulfur, and CO2. The main species in solid residues were S8 species having the bond distances of 1.98 Å with the coordination number of 1.15. This result indicates that SF6 may be completely mineralized and converted to elemental sulfur and salts. Based on FTIR spectra, the decompostion ability of SF6 is ZSM-5＞Beta＞Y and only ZSM-5 can degrade CF4, C3F8, and C4F8. The adsorption capacities of C3F8 and C4F8 is Beta＞ZSM-5＞Y. It may be resulted that the pore size selectivity of Y＞Beta＞ZSM-5 that moelcular size of C4F8 is similar to the pore size of zeolite Beta and ZSM-5. MOFs have much large pore size that PFCs molecules may be desorbed easily. Moreover, The government policy of new options by industries for reducing PFCs emissions included the technologies of adsorption recovery, mineralization and catalytic decomposition will be warranted and environmentally attractive in the future.

Perfluorinated Compounds, Oxalate/Zeolite, Mineralization/Catalytic Decomposition