Catalytic esterification of pyruvic acid with ethanol via amphiphile-templated SAPO-5 hierarchical molecular sieves
Document Type
Article
Publication Date
3-1-2025
Abstract
Soft-templating synthesis of hierarchical SAPO-5 zeolites using dimethyloctadecyl3-(trimethoxysilyl)propyl] ammonium chloride (TP), cetyltrimethylammonium bromide (CTA) and cetylpyridinium chloride (CP) is reported where the effects of these amphiphilic molecules on crystallization, morphological and structural characteristics of SAPO-5 are investigated. The results reveal that these compounds have shown their exceptional ability in molecular confinement and packing during the crystallization process which alter the morphological (crystal size and shape) and structural (porosity and acidity) properties of SAPO-5. The resulting SAPO-5 solids exhibit distinct morphologies having hierarchical porosity, and they enhance the catalytic esterification of pyruvic acid to produce ethyl pyruvate. TP-SAPO-5 with the highest hierarchical factor (HF = 0.065) and second highest in acidity (0.73 mmol/g) is the best catalyst (in terms of conversion and selectivity) compared to its hierarchical counterparts. Its performance (92.0 f 1.2 % conversion, 85.9 f 0.3 % selectivity) after parametric optimization is comparable as homogenous HCl and H2SO4 catalysts (88-92 % conversion, 84-92 % selectivity), and is much superior than H-Y, H-MOR, SAPO-34 zeolites (56-100 % conversion, 67-76 % selectivity). The hierarchical TP-SAPO-5 is also reusable up to five reaction cycles which offer it as an ideal green and selective acid catalyst for upgrading of biomass products.
Keywords
SAPO-5, Hierarchical structure, Amphiphiles, Esterification of pyruvic acid, Ethyl pyruvate
Divisions
InstituteofBiologicalSciences,nanotechnology
Funders
Ministry of Education, Malaysia (FRGS/1/2022/STG05/USM/02/12)
Publication Title
Materials Chemistry and Physics
Volume
333
Publisher
Elsevier
Publisher Location
PO BOX 564, 1001 LAUSANNE, SWITZERLAND