Ammoxidation of Toluene on Coke-Covered Alumina

The catalytic activity of coke formed during the ammoxidation of toluene was studied as a function of time-on-stream. The changes in catalytic activity could be explained in terms of competing rates of formation of active centres (coke) and of their encapsulation within the growing coke mass. The acid strength of coke-forming centres on alumina, the concentration of paramagnetic centres in the coke and the elemental composition of the coke were examined and related to the nature of the ammoxidation process. Some of the chemical character of the coke was evaluated using IR spectrophotometry.