PROBLEMS IN PREPARATION OF FEZSM-5 CATALYSTS

FeZSM-5 catalysts for SCR of NO to N-2 can be made in a highly durable form that may be useful for automotive exhaust cleanup, but not prese ntly reproducible. Herein we outline the properties and characteristic s of good versus poor catalysts and provide results of experiments tha t effect the properties of the final preparation. It is shown how Moss bauer characterization will be useful in understanding the changes tha t occur as the catalysts age. The problem has not yet been resolved. T his letter is meant to challenge research by others.