Reactivity and catalytic activity of copper chlorides. Part 2.—Catalysis of the chlorination of propane by CuC1x(1 ⩽x⩽ 2)

Abstract

CuCl is catalytically inactive for chlorination of propane, but CuCl_x prepared by chlorination of CuCl is active from x= 1.2 to x= 2, with peaks in the (activity, composition) curve at roughly x= 1.57 and x= 1.78. The activation energy is 2.3 ± 1.2 kcal mol^–1. For CuCl₂, pressure dependences correspond to a Langmuir-Hinshelwood mechanism with strongly adsorbed propane and weakly adsorbed chlorine. Release of HCl from the catalyst is markedly delayed.

The (activity, composition) curve correlates closely with the curve for effect of propane on the CuCl/Cl₂ reaction, and with a curve for total amount of diffusing material calculated from the data in part one. It is proposed that the diffusing species is Cu⁺, which can accept a proton, originally adsorbed as neutral H on Cu²⁺, in homolytic fission of C₃H₈.