Selected properties and electronic spectra for a series of copper(II) alkali, alkaline earth, and lanthanide metal chloride oxyhydrochlorination catalysts on alumina

Abstract

Abstract Some selected properties for a series of copper(II) oxyhydrochlorination (OHC) catalysts were determined. Copper(II) alkali, alkaline earth, and lanthanide metal chloride salts were supported on alumina in each case. The electronic spectral frequencies, crystal field band shapes, and band assignments were used to define and correlate some of the microscopic and macroscopic characteristics of these systems. The overall fluidization properties are hereby related to substructure in each matrix. After a thermal cycling to 300 °C for 24 hr, the electronic spectra and X-ray powder diffraction patterns run at 25 °C, provide evidence for the existence of two separate and distinctly different anionic defect site symmetries about copper(II). In the presence of K + and Cs + ions a pseudotetrahedral, D 2 d , CuCl 4 2− ion is observed and with Mg 2+ , La 3+ , and Li + ions, a tetragonally distorted O h , CuCl 6 4− , ion is found. The D 2 d system has been reported to have much better fluidization properties and subsequently improved reaction rates because of better particle size distribution during OHC operation.