Open AccessPhosgene Synthesis Catalysis: The Influence of Small Quantities of Bromine in the Chlorine Feedstream
Author(s) -
Giovanni E. Rossi,
John M. Winfield,
Nathalie Meyer,
Don H. Jones,
R. H. Carr,
David Len
Publication year - 2021
Publication title -
industrial and engineering chemistry research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.878
H-Index - 221
eISSN - 1520-5045
pISSN - 0888-5885
DOI - 10.1021/acs.iecr.1c00088
Subject(s) - phosgene , bromine , catalysis , chemistry , chlorine , molar ratio , reaction rate , volumetric flow rate , inorganic chemistry , organic chemistry , thermodynamics , physics
The effect of relatively low concentrations of Br 2(g) in the Cl 2(g) feedstock for phosgene synthesis catalysis via the reaction of CO (g) and Cl 2(g) over activated carbon (Donau Supersorbon K40) is explored. Under the stated reaction conditions and in the absence of a catalyst, BrCl (g) forms from the reaction of Cl 2(g) and Br 2(g) . Phosgene synthesis over the catalyst at 323 K is investigated for Br 2(g) :Cl 2(g) molar flow ratios in the range 0-1.52% (0-15,190 ppm) and shows enhanced rates of phosgene production. Maximum phosgene production is observed at a Br 2(g) :Cl 2(g) molar flow ratio of 1.52% (15,190 ppm), which corresponds to an enhancement in the rate of phosgene production of ∼227% with respect to the phosgene flow rate observed in the absence of an incident bromine co-feed. A reaction model is proposed to account for the experimental observables, where BrCl (g) is highlighted as a significant intermediate. Specifically, enhanced rates of phosgene production are associated with the dissociative adsorption of BrCl (g) that indirectly increases the pool of Cl (ad) available for reaction.