Active sites in carbon-catalyzed phosgene synthesis from gaseous CO and Cl2 have been identified using C60 fullerene as a model catalyst. The carbon atoms distorted from sp2 coordination in non-planar carbon units are concluded to generate active Cl2. Experiments and density functional theory calculations indicate the formation of a surface-bound [C60⋯Cl2] chlorine species with radical character as key intermediate during phosgene formation. It reacts rapidly with physisorbed CO in a two-step Eley-Rideal-type mechanism.
- density functional calculations
- reaction mechanisms