Nitrogen Modified Carbon Nano-Materials as Stable Catalysts for Phosgene Synthesis

Abstract

The carbon-catalyzed reaction of Cl2 and CO constitutes the most important industrial route to phosgene. Although defects in carbon lead to surface chemical reactions, direct polarization of C-heteroatom bonds induces a more successful Cl2 catalytic activation, the rate-determining step in the overall catalytic cycle. The interplay between the electron-donating and -withdrawing ability of the incorporated nitrogen substituents on the formation and stabilization of active sites was examined by X-ray photoelectron and Raman spectroscopy. Mechanistic studies indicate that the polarized Cl2 induced by the direct interaction of Cl2 with a strongly electron-deficient carbon site in close proximity to a nitrogen substituent is essential for phosgene production. Nitrogen substitution into ordered carbon materials led to very active and stable carbon catalysts for COCl2 synthesis.