Selective Hydrogen Cyanide Synthesis from CFC12 (CCl2F2) and Ammonia Over Metal Catalysts Supported on LaF3 and Activated Charcoal.

Abstract The applicability of supports such as LaF3, activated charcoal and Cr2O3 to the new reaction, CCl2F2 + 5 3 NH3→HCN + 2HCl + 2HF + 1 3 N2 was examined and it was found that TiO2 itself reacted with CFC12 to give carbon monoxide and carbon dioxide even at 673 K in addition to hydrogen cyanide formation. LaF3 did not react with CFC (chlorofluorocarbon) even at 823 K so that it could be considered suitable for use as a catalyst support. Au(1 wt.-%)/LaF3 and Pt(1 wt.-%)/LaF3 were effective for hydrogen cyanide formation and hydrogen cyanide selectivity reached 77–78% at 823 K. Activated charcoal was also suitable for use as a catalyst support and hydrogen cyanide was formed selectively (72–84%) over Rh(1 wt.-%)/AC and Pd(1 wt.-%)/AlF3/AC catalysts at 823 K.