Optical Measurement of the Specific Chromia Area of Chromia—Alumina Catalysts

The optical reflectances of chromia—alumina catalysts in the visible and ultraviolet regions have been determined and, at the same time, the specific chromia surface areas measured by oxygen chemisorption. A relationship was found between the intensities of the charge-transfer bands of Cr6+ and the extent of chromia area, which permits one to determine the chromia area of a chromia—alumina catalyst from the optical reflectance spectra.