Wang, Guanchen (2025) Synthesis Of Silicoaluminophosphate Zeolite Catalysts Directed By Benzyltrimethylammonium Hydroxide Template For The Chemical Production Of Biofuel Additives. Masters thesis, Universiti Sains Malaysia.
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Abstract
Silicoaluminophosphate (SAPO) zeolites are very useful catalysts. Usually, they are synthesized with aliphatic quaternary ammonium compounds as organic template. However, benzyltrimethylammonium hydroxide (BTMAOH) containing cyclic functional group as a template has not been studied. Here, the crystallization of SAPO-34 and SAPO-20 zeolites using BTMAOH is studied by following their evolutional formation. The BTMA+ has shown its effective structure-directing and pore-filling roles whereby pure SAPO-34 and SAPO-20 with unique surface properties (surface area, porosity, acidity) are formed after 24 and 42 h at 180 °C. Compared with SAPO-20, SAPO-34 with larger pore size exhibits better catalytic activity (conversion 100%, ethyl levulinate (EL) yield 72.5%) in microwave-assisted furfuryl alcohol (FA) ethanolysis. The spent SAPO-34 catalyst is stable and recyclable, offering it as a cost-effective catalyst for various petrochemical reactions. This work also studies the preparation of hierarchical SAPO-5 using various surfactants, namely dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride (TP), hexadecyltrimethylammonium bromide (CTA) and hexadecylpyridinium chloride (CP). The results show that these ionic compounds experience interactions with inorganic reagents during crystallization, which in turn altering the morphological (crystal size and shape) and structural (porosity and acidity) properties of SAPO-5. Among hierarchical SAPO-5 samples, TP-SAPO-5 with the highest hierarchical factor (HF = 0.074) and second highest acidity (0.73 mmol·g-1) is the best catalyst for producing ethyl pyruvate (EP) via esterification. After parametric optimization, its performance (conversion 92.0%, selectivity 85.9%) is comparable to homogeneous HCl and H2SO4 catalysts (conversion 88-92%, selectivity 84-92%) and much superior than H-Y, H-MOR, SAPO-34 zeolites (conversion 56-100%, selectivity 67-76%). The hierarchical TP-SAPO-5 is also reusable for up to five reaction cycles, making it as a green and excellent catalyst for biomass product conversion.
| Item Type: | Thesis (Masters) |
|---|---|
| Subjects: | Q Science > QD Chemistry > QD1-999 Chemistry |
| Divisions: | Pusat Pengajian Sains Kimia (School of Chemical Sciences) > Thesis |
| Depositing User: | Mr Aizat Asmawi Abdul Rahim |
| Date Deposited: | 02 Oct 2026 01:53 |
| Last Modified: | 02 Oct 2026 01:53 |
| URI: | http://eprints.usm.my/id/eprint/65081 |
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