A study of the preactivation of a copper chromite catalyst

Abstract

Copper chromite was studied for the reductive alkylation of aniline with acetone to N-isopropylaniline as a function of the catalyst prereduction conditions. In order to optimize prereduction conditions the catalyst was reduced in an atmosphere of hydrogen at different temperatures: 100, 150, 200, 250, 300, 350, 400 and 450°C and for different durations. The activity of reduced catalysts was determined. The X-ray diffractograms of all catalyst samples were taken. Partially reduced copper species were determined by chemical analysis. Prereduced catalyst having more Cu(I) species showed a greater activity than the fresh catalyst containing only Cu(II) ions and than that of the catalyst containing more Cu(0) ions. From these studies it was inferred that the active sites of the copper chromite catalyst used for reductive alkylation of amines are Cu(I) species.