Selective hydrogen cyanide synthesis from CFC12 (CCl 2F 2) and ammonia over metal catalysts supported on LaF 3 and activated charcoal

Abstract

The applicability of supports such as LaF 3, activated charcoal and Cr 2O 3 to the new reaction, CCl 2F 2 + 5 3 NH 3→HCN + 2HCl + 2HF + 1 3 N 2 was examined and it was found that TiO 2 itself reacted with CFC12 to give carbon monoxide and carbon dioxide even at 673 K in addition to hydrogen cyanide formation. LaF 3 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.-%)/LaF 3 and Pt(1 wt.-%)/LaF 3 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.-%)/AlF 3/AC catalysts at 823 K.