Structural behaviour of copper chloride catalysts during the chlorination of CO to phosgene

DOI: 10.1039/C8FD00005K

Authors: Shaoliang Guan (Cardiff University; University of Glasgow) , Philip R. Davies (Cardiff University) , Emma K. Gibson (UK Catalysis Hub; Diamond Light Source; University College London) , David Lennon (University of Glasgow) , Giovanni E. Rossi (University of Glasgow) , John M. Winfield (University of Glasgow) , June Callison (UK Catalysis Hub) , Peter P. Wells (UK Catalysis Hub; Diamond Light Source; University of Southampton) , David J. Willock (Cardiff University)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Faraday Discussions

State: Published (Approved)
Published: February 2018
Diamond Proposal Number(s): 10306

Abstract: The interaction of CO with an attapulgite-supported Cu(II)Cl2 catalyst has been examined in a micro-reactor arrangement. CO exposure to the dried, as-received catalyst at elevated temperatures leads to the formation of CO2 as the only identifiable product. However, phosgene production can be induced by a catalyst pre-treatment where the supported Cu(II)Cl2 sample is exposed to a diluted stream of chlorine. Subsequent CO exposure at  370C then leads to phosgene production. In order to investigate the origins of this atypical set of reaction characteristics, a series of x-ray absorption experiments were performed that were supplemented by DFT calculations. XANES measurements establish that at the elevated temperatures connected with phosgene formation, the catalyst is comprised of Cu+ and a small amount of Cu2+. Moreover, the data show that unique to the chlorine pre-treated sample, CO exposure at elevated temperature results in a short-lived oxidation of the copper. On the basis of calculated CO adsorption energies, DFT calculations indicate that a mixed Cu+/Cu2+ catalyst is required to support CO chemisorption.

Subject Areas: Chemistry


Instruments: B18-Core EXAFS

Documents:
C8FD00005K.pdf