Zeolite catalysts for hydrocarbon conversion - calcined in two stages to prevent deactivation

摘要

Catalysts with a zeolite carrier, treated with an ion-exchange soln contg NH4 and Pd and/or Pt ions in ratio of =10:1, to give a noble metal content of 0.05-5 wt. % are calcined in a controlled flow of O2 contg. gas at an initial temp of 200-400 degrees C and subsequently at 400-900 degrees C. - Used for conversion of hydrocarbons, eg hydro-cracking polymerisation, alkylation and de-alkylation, reforming and esp isomerisation of lower hydrocarbons in presence of N2. deactivation of the catalysts during calcination, due to local overheating and sintering of the metal by the heat of the NH3 oxidn is prevented.