Nanostructured surfaces

Effect of Zn-BEA zeolites dealumination on their catalytic perfomance in propane dehydrogenation to propylene with CO2

Orlyk S.M.1, Chedryk V.I.1, Kyriienko P.I.1, Kapran A.Yu.1, Balakin D.Yu.2, Dzwigaj S.3
 1L.V. Pisarzhevskii Institute of Physical Chemistry, NAS of Ukraine, 31 Prosp. Nauky, 03028 Kyiv, Ukraine.
E-mail: ayukapran@ukr.net
2Institute of Physics, NAS of Ukraine, 46 Prosp. Nauky, 03028 Kyiv, Ukraine.
3Laboratoire de Réactivité de Surface, Sorbonne Université-CNRS, UMR 7197, 4 place Jussieu, Paris, F-75005, France.

Oxidative dehydrogenation processes of alkanes, in particular propane to propylene with CO2 (DHP-CO2), is considered a promising alternative to the oil-based cracking processes of propylene production [1, 2].
The influence of preliminary dealumination of BEA zeolite on the acid-base characteristics   of    Zn-BEA   compositions   and    their   catalytic   properties   in 
the DHP-CO2 process is studied. 
Full pre-dealumination of starting BEA specimen followed by incorporation of zinc cations in the T-positions of the zeolite framework is shown to cause a halving in the total acidity and basicity of the ZnSiBEA sample compared to ZnAlBEA.
The ZnSiBEA catalyst, characterized by a more developed mesoporous nanostructure and specific surface area, the predominance of acidic (Zn2+ cations) and basic (O2- anions and oxygen vacancies) sites of medium strength as well as an absence of protonic acid centers in contrast to ZnAlBEA and partially dealuminated ZnAlSiBEA specimen, is superior to them concerning the achieved selectivity of 74% and yield of 22% with respect to propylene produced.
Regeneration of the ZnSiBEA zeolite by calcining in situ is shown to provide an increase in the selectivity to 94% and yield to 30% with reference to propylene in the DHP-CO2. 

1. Atanga M.A., Rezaei F., Jawad A., Fitch M., Rownaghi A.A. Oxidative dehydrogenation of propane to propylene with carbon dioxide // Appl Catal B Environ.- 2018.- 220.- P. 429-445. 
2. Otroshchenko T., Jiang G., Kondratenko V.A., Rodemerck U., Kondratenko E. V. Current status and perspectives in oxidative, non-oxidative and CO2-mediated dehydrogenation of propane and isobutane over metal oxide catalysts // Chem Soc Rev.-2021.- 50. -P. 473-527.