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Improving the hydrothermal stability of zeolite Y by La(3+) cation exchange as a catalyst for the aqueous-phase hydrogenation of levulinic acid

La(3+) cation exchange is shown to improve the hydrothermal stability and catalytic activity of bifunctional zeolite Pt/Y catalysts in the aqueous-phase hydrogenation of levulinic acid (LA) with formic acid (FA) as hydrogen source. La(3+) cation exchange of zeolite Y (n(Si)/n(Al) = 16) was conducted...

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Detalles Bibliográficos
Autores principales: Vu, Hue-Tong, Goepel, Michael, Gläser, Roger
Formato: Online Artículo Texto
Lenguaje:English
Publicado: The Royal Society of Chemistry 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8694756/
https://www.ncbi.nlm.nih.gov/pubmed/35423095
http://dx.doi.org/10.1039/d0ra08907a
Descripción
Sumario:La(3+) cation exchange is shown to improve the hydrothermal stability and catalytic activity of bifunctional zeolite Pt/Y catalysts in the aqueous-phase hydrogenation of levulinic acid (LA) with formic acid (FA) as hydrogen source. La(3+) cation exchange of zeolite Y (n(Si)/n(Al) = 16) was conducted both in aqueous solution and in the solid state. The hydrothermal stability of La(3+)-containing zeolite Y probed by exposure to the reaction mixture (0.2 mol L(−1) LA, 0.6 mol L(−1) FA) at 473 K under autogenous pressure for 24 h improves with increasing La content. The material exhibiting the highest La content (0.5 mmol g(−1)) is the most stable with a preservation of 25% of the initial specific micropore volume after the hydrothermal treatment, whereas unmodified zeolite Y completely loses its microporosity. A new procedure using DRIFTS is a useful supplementary tool for quantifying the framework degradation of Y-type zeolites after hydrothermal treatment. Bifunctional Pt/Y catalysts after La(3+) cation exchange are more active than the parent Y-zeolite for the hydrogenation of LA to γ-valerolactone (GVL), with significant enhancements in LA conversion, i.e., 94% vs. 42%, and GVL yield, i.e., 72% vs. 34%., after 24 h.