A CoAPO-34 derived from a triclinic precursor prepared in the presence of HF
Abstract
The fluoride route of synthesis of AIPO,-34 is also successful in the preparation of its cobalt modified product (CoAPO-34). The triclinic precursor of CoAPO-34 has been synthesized in the presence of HF and piperidine. Although two different Al sites are available for cobalt(ll) substitution (i.e., tetrahedral and octahedral sites), cobalt(ll) substitutes exclusively the tetrahedral aluminum. Calcination of the as-synthesized material results in oxidation of Cofll). This is evident from the electron absorption, electron paramagnetic resonance, and infrared measurements. The
calcined product exhibits a particular sensitivity to humidity: upon hydration, the chabazite struc ture transforms to a new one. However, the hydration is a reversible process: thermal evacuation of the hydrated sample causes a complete return to the chabazite material. In comparison with the CoAPO-34 obtained in a nonfluoride medium, the CoAPO-34 prepared in this work exhibits a higher thermal stability.
Keywords:
Molecular sieve / cobalt-substituted aluminophosphate / triclinic CoAPO-34 / fluoride synthesis route / cobalt(ll) oxidation / u.v.-vis and i.r. spectroscopy / solid-state n.m.r.Source:
ZEOLITES, 1997, 18, 115-118Publisher:
- Elsevier Science Inc.
Institution/Community
Tehnološko-metalurški fakultetTY - JOUR AU - Rajić, Nevenka AU - Ristić, Alenka AU - Tuel, Alain AU - Kaučič, Venčeslav PY - 1997 UR - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6390 AB - The fluoride route of synthesis of AIPO,-34 is also successful in the preparation of its cobalt modified product (CoAPO-34). The triclinic precursor of CoAPO-34 has been synthesized in the presence of HF and piperidine. Although two different Al sites are available for cobalt(ll) substitution (i.e., tetrahedral and octahedral sites), cobalt(ll) substitutes exclusively the tetrahedral aluminum. Calcination of the as-synthesized material results in oxidation of Cofll). This is evident from the electron absorption, electron paramagnetic resonance, and infrared measurements. The calcined product exhibits a particular sensitivity to humidity: upon hydration, the chabazite struc ture transforms to a new one. However, the hydration is a reversible process: thermal evacuation of the hydrated sample causes a complete return to the chabazite material. In comparison with the CoAPO-34 obtained in a nonfluoride medium, the CoAPO-34 prepared in this work exhibits a higher thermal stability. PB - Elsevier Science Inc. T2 - ZEOLITES T1 - A CoAPO-34 derived from a triclinic precursor prepared in the presence of HF EP - 118 SP - 115 VL - 18 UR - https://hdl.handle.net/21.15107/rcub_technorep_6390 ER -
@article{ author = "Rajić, Nevenka and Ristić, Alenka and Tuel, Alain and Kaučič, Venčeslav", year = "1997", abstract = "The fluoride route of synthesis of AIPO,-34 is also successful in the preparation of its cobalt modified product (CoAPO-34). The triclinic precursor of CoAPO-34 has been synthesized in the presence of HF and piperidine. Although two different Al sites are available for cobalt(ll) substitution (i.e., tetrahedral and octahedral sites), cobalt(ll) substitutes exclusively the tetrahedral aluminum. Calcination of the as-synthesized material results in oxidation of Cofll). This is evident from the electron absorption, electron paramagnetic resonance, and infrared measurements. The calcined product exhibits a particular sensitivity to humidity: upon hydration, the chabazite struc ture transforms to a new one. However, the hydration is a reversible process: thermal evacuation of the hydrated sample causes a complete return to the chabazite material. In comparison with the CoAPO-34 obtained in a nonfluoride medium, the CoAPO-34 prepared in this work exhibits a higher thermal stability.", publisher = "Elsevier Science Inc.", journal = "ZEOLITES", title = "A CoAPO-34 derived from a triclinic precursor prepared in the presence of HF", pages = "118-115", volume = "18", url = "https://hdl.handle.net/21.15107/rcub_technorep_6390" }
Rajić, N., Ristić, A., Tuel, A.,& Kaučič, V.. (1997). A CoAPO-34 derived from a triclinic precursor prepared in the presence of HF. in ZEOLITES Elsevier Science Inc.., 18, 115-118. https://hdl.handle.net/21.15107/rcub_technorep_6390
Rajić N, Ristić A, Tuel A, Kaučič V. A CoAPO-34 derived from a triclinic precursor prepared in the presence of HF. in ZEOLITES. 1997;18:115-118. https://hdl.handle.net/21.15107/rcub_technorep_6390 .
Rajić, Nevenka, Ristić, Alenka, Tuel, Alain, Kaučič, Venčeslav, "A CoAPO-34 derived from a triclinic precursor prepared in the presence of HF" in ZEOLITES, 18 (1997):115-118, https://hdl.handle.net/21.15107/rcub_technorep_6390 .