UBC Theses and Dissertations
The reactivity and catalytic activity of copper chlorides Ng, Ching Fai
The reactivity of copper chloride (CuC1[subscript x], 1 < x < 2) towards chlorine and its catalytic activity in the chlorination of propane have been studied. The oxidation of copper (I) chloride by chlorine was found to be diffusion controlled after the first 25% of reaction. For the chlorination of propane, CuC1 was catalytically inactive, CuC1₂ was active, but the maximum activity was found in the range CuC1₁․₅ to CuC1₁․₈ with two peaks at roughly CuC1₁․₅₇ and CuC1₁․₇₈. Both reactions appear to have an active centre in common — a Cu⁺ ion which is capable of accepting a proton. The phase of maximum catalytic activity is a highly defective CuC1₂ phase containing such centres. The mechanism for the catalytic chlorination involves the homolytic splitting of C₃H₈ and stabilization of surface radicals through proton transfer into the bulk. No compound other than CuC1 and CuC1₂ was found in the CuC1x system by X-ray powder studies. However, the results of X-ray powder, electrical conductivity and magnetic susceptibility studies provide convincing evidence for the existence of a defective CuC1₂ phase with interstitial cations as well as a cation-deficient CuC1 phase in CuC1x. Furthermore, these results are consistent with a structural change at x ∼1.63 as suggested also by the kinetic studies. While the present work shows many interesting features of the CuC1x system, there is plenty of room for further exploration in this hitherto virtually unknown field. Suggestions for future work related to the present findings are outlined in this thesis.
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