Deammoniation reaction of ammonium X zeolite

Journal Article · Thu Jan 31 23:00:00 EST 1980 · J. Catal.; (United States)

DOI:https://doi.org/10.1016/0021-9517(80)90392-9· OSTI ID:6448863

Chu, P; Dwyer, F G

Sodium X zeolite was 93% ammonium-exchanged in a continuous-flow process with a 1:1 mixture of ammonium chloride and ammonium hydroxide at 80/sup 0/C. The ammonium X zeolite was vacuum-dried at room temperature. Its chemical analysis was (NH/sub 4/)/sub 78/(H/sub 3/O)/sub 5/NaAl/sub 84/Si/sub 108/O/sub 384/. Differential thermal analysis gave endotherms at 100/sup 0/C for water desorption and at 175/sup 0/ and 270/sup 0/C for ammonia desorption from the sodalite cage and supercage, respectively, i.e., the ammonia desorption occurred about 70/sup 0/C below that of the corresponding Y zeolite. No dehydroxylation peak was observed, although crystallinity loss set in below 200/sup 0/C and the sample was essentially amorphous at 400/sup 0/C; dehydroxylation was presumably masked by the deammoniation peaks. An exothermic peak at 1040/sup 0/C was associated with the transition from the amorphous to mullite phase. Thermograms of a 60% ammonium-exchanged X zeolite showed mainly the 270/sup 0/C peak, i.e., the ammonium was mainly located in the supercage. The thermogram of a 93% NH/sub 4/X zeolite, that was partly ion-exchanged with cesium, showed mainly the 175/sup 0/C peak, i.e., the supercage ammonium was exchanged with cesium and the ammonium in the sodalite cage remained.

• Research Organization: Mobil Res. Dev. Corp.
• OSTI ID: 6448863
• Journal Information: J. Catal.; (United States), Journal Name: J. Catal.; (United States) Vol. 61:2; ISSN JCTLA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ALKALI METAL COMPLEXES
ALKALI METALS
ALUMINIUM COMPLEXES
AMMONIUM CHLORIDES
AMMONIUM COMPOUNDS
AMMONIUM HALIDES
AMMONIUM HYDROXIDES
AMORPHOUS STATE
CESIUM
CHALCOGENIDES
CHEMICAL COMPOSITION
CHLORIDES
CHLORINE COMPOUNDS
COMPLEXES
CRYSTAL STRUCTURE
DESORPTION
DISPERSIONS
ELEMENTS
HALIDES
HALOGEN COMPOUNDS
HIGH TEMPERATURE
HYDROGEN COMPOUNDS
HYDROXIDES
INORGANIC ION EXCHANGERS
ION EXCHANGE
ION EXCHANGE MATERIALS
MATERIALS
MEDIUM TEMPERATURE
METALS
MINERALS
MIXTURES
OXIDES
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
SILICON COMPOUNDS
SILICON OXIDES
SODIUM COMPLEXES
THERMAL ANALYSIS
WATER
ZEOLITES