Process for the preparation of an Fe (II) or Mn (II) exchanged zeolite

摘要

Production or a Fe (II)- or Mn (II) exchanged zeolites, comprises suspending the exchanged zeolite in an aqueous Fe (II) salt solution or Mn (II) salt solution and ion-exchanging. The novelty is that a reductant is dissolved in the Fe (II) salt solution or the Mn (II) salt solution, and the reductant reduces Fe (III) formed by oxygen contamination, or Mn (III)/Mn (IV) to Fe (II) or Mn (II).