IGNITION OF AMMONIA ON VARIOUS ZEOLITIC SUBSTRATES

The natural zeolites chabazite and clinoptilolite, and synthetic zeoli tes A and X in their ammonium forms were tested by thermodilatometry. Chabazite, A and X zeolites appeared to catalyze ammonia combustion, w hereas clinoptilolite did not. The thermal effects relating to ammonia combustion were ascribed either to different heating rates or to diff erent catalytic activity of the various zeolitic substrates. The diffe rent ignition temperatures of ammonia measured on different zeolitic s ubstrates were taken to be a measure of the catalytic activity of the zeolitic substrate itself. (C) 1997 Elsevier Science B.V.