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(Zn)MgAl Hydrotalcite-Based Composite Oxide Nanostructures for Propane Dehydrogenation.
- Source :
- ACS Applied Nano Materials; 11/24/2023, Vol. 6 Issue 22, p20652-20659, 8p
- Publication Year :
- 2023
-
Abstract
- Different amounts of Zn contained MgAl-layered double hydrotalcites topologically transformed into mixed oxide (xZn-O) nanomaterials through calcination at a high temperature. The degree of polymerization and reducibility of ZnO<subscript>x</subscript> species have been systematically investigated, as they are closely linked to the activity of propane dehydrogenation (PDH). For the xZn-O (x < 25%) catalysts, highly dispersed Zn species dominate owning to the strong lattice confinement effect of MgAl<subscript>x</subscript>O<subscript>y</subscript> supports. These catalysts exhibit a high turnover frequency (TOF) value, 93% propylene selectivity, and a slow increase in C<subscript>3</subscript>H<subscript>8</subscript> conversion due to their strong resistance to over reduction. With an increase in Zn content, surface-supported ZnO nanoparticles and bulk ZnO crystal species emerge. Based on the results of characterization and calculation, as the degree of polymerization of the ZnO<subscript>x</subscript> species increases, they become more easily reduced, and the activation energy for C<subscript>3</subscript>H<subscript>6</subscript> formation decreases, suggesting that the coordinatively unsaturated ZnO<subscript>x</subscript> species nearby oxygen vacancies are the active sites for PDH. However, these also lead to a decrease in C<subscript>3</subscript>H<subscript>6</subscript> selectivity and an increase in coke selectivity (deactivation constant). Therefore, the appropriate degree of polymerization and reducibility of ZnO<subscript>x</subscript> species is critical for achieving efficient catalytic PDH. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 25740970
- Volume :
- 6
- Issue :
- 22
- Database :
- Complementary Index
- Journal :
- ACS Applied Nano Materials
- Publication Type :
- Academic Journal
- Accession number :
- 173860692
- Full Text :
- https://doi.org/10.1021/acsanm.3c03243