Akademik Veri Yönetim Sistemi
SILICON, cilt.0, sa.0, 2023 (SCI-Expanded)
Aerogels, one of the first materials that come to mind in relation to lightweight and solid materials, have gained a place in various applications due to their remarkable properties. In this study, silica aerogels were synthesized with a hydro(solvo)thermal-supported sol-gel synthesis procedure. In order to determine the optimum conditions for the synthesis of the silica aerogel, the effect of some parameters was investigated. Nano- and micro-sized particles such as SiO2 and carbon particles were embedded/doped into the silica aerogel to obtain interpenetrating network structures. Then, the -NH2 functional group was added to the structure by using APTES modification and protonation was achieved by HCl treatment. All these structures were successfully used as catalysts for the dehydrogenation of NaBH4 in methanol. When CP-APTES-HCl silica aerogel was used as catalyst, the activation energy, enthalpy and entropy values for NaBH4 methanolysis were calculated as 38.25 kJmol(-1), 35.79 kJmol(-1), and -156.11 J mol(-1) K-1, respectively. The calculated hydrogen generation rate at 298 K was 1860 mL min(-1) g(-1). The CP-APTES-HCl silica aerogel catalyst was used 6 times in a row in the same medium. The results showed that 100% conversion was achieved with each use. Although there was a slight decrease in activity with repeated use, a value close to 70% was obtained for the 6(th) use.