Synthesis and characterization of o-IMPA/p-IMPA functionalized graphene oxide composites for efficient hydrogen generation via NaBH4 methanolysis
Journal of Molecular Structure, cilt.1378, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 1378
- Basım Tarihi: 2026
- Doi Numarası: 10.1016/j.molstruc.2026.147204
- Dergi Adı: Journal of Molecular Structure
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Chemical Abstracts Core, Chimica, Compendex, INSPEC, Academic Search Ultimate (EBSCO), Engineering Source (EBSCO)
- Anahtar Kelimeler: GO, Hydrogen production, Methanolysis, Organic catalyst (thymol), Sodium borohydride
- Eskişehir Osmangazi Üniversitesi Adresli: Evet
Özet
This study investigates the preparation of composites comprising graphene oxide (GO) and newly synthesized organic structures, focusing on their catalytic activities in hydrogen production via the methanolysis of sodium borohydride (NaBH4). Employing the Sonogashira coupling reaction, we successfully synthesized 2-(3-(2-isopropyl-5-methylphenoxy)prop-1-yn-1-yl)aniline (o-IMPA) and 4-(3-(2-isopropyl-5-methylphenoxy)prop-1-yn-1-yl)aniline (p-IMPA). Graphene oxide was synthesized utilizing a modified Hummers’ method, and subsequent modification with organic molecules was accomplished through the Steglich amidation reaction. The characterization of the synthesized catalysts was rigorously conducted using techniques such as XRD, Raman spectroscopy, FTIR, SEM-EDX, and DFT calculations. The catalytic performance of the composite catalysts was assessed in a controlled NaBH4 methanolysis reaction, utilizing 0.01 g of catalyst, 0.125 g of NaBH4, 10 mL of methanol, and maintaining a temperature of 30°C. Under these conditions, the o-IMPA/GO composite demonstrated a hydrogen production rate of 27,988 mL/min.gcat, while the p-IMPA/GO composite achieved a production rate of 21,820 mL/min.gcat. Further optimization studies conducted on the o-IMPA/GO catalyst, which exhibited a substantial hydrogen production rate, identified the optimal reaction conditions as 0.005 g of catalyst, 2 mL of methanol, 0.125 g of NaBH4, and a temperature of 60°C. Within these parameters, a remarkable hydrogen production rate of 92,017 mL/min.gcat was attained. Kinetic analysis revealed that the activation energy for the o-IMPA/GO catalyst was calculated to be 26.26 kJ/mol. Furthermore, the 5% o-IMPA/GO catalyst retained 81.44% of its initial activity after five consecutive cycles, demonstrating good operational stability and reusability.