Yeşil sentezle (hidrotermal/solvotermal) karbon kuantum noktaları sentezi; dimetil aminboran ve sodyum borhidrürde hidroliz epkimelerindeki katalitik performanslarının teorik ve deneysel incelemesi
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Tarih
2024
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Siirt Üniversitesi
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Hidrojen depolama olarak kullanılan kimyasal hidritler, hidrojenin kimyasal bileşiklerde güvenli olarak depolanması, verimli bir şekilde taşınması ve istenildiğinde hidrojeni serbest bırakılmasının en etkili yollarından biri olarak görülmektedir. Bu tez çalışmasında; Şu ana kadar kimyasal hidrojen depolama malzemelerinden olan ve en fazla kullanılan Sodyum borhidrür (SBH)'ün yanında hidrojen depolama kapasitesi yüksek ve hidrojen depolama malzemeleri arasında en umut verici olan Dimetil aminboran (DMAB) kullanıldı. Bununla birlikte üreden, hidrotermal ve solvotermal şartlar altında elde edilen karbon kuantum noktaları (CQD) üzerine Ni metali doplanarak, elde edilen katalizörlerin (farklı yükleme türü, farklı NaOH etkisi, farklı katalizör miktarı, farklı borhidrür konsantrasyonu, sıcaklık ve tekrar kullanılabilirlik) hidrolizleri yapılarak SBH ve DMAB'ın hidrojen üretimi üzerine katalitik performansları incelenmiştir. Ayrıca bu tez çalışmasında moleküler dinamik programı ile teorik farklı sıcaklıklarda hidroliz gerçekleştirilerek hem NaBH4 hem de DMAB için terik hesaplama yapıldı. Bunun da deneysel çalışmalarda gerçekleştirilen hidroliz sonuçlarıyla bire bir ötüştüğü görülmüştür. Son olarak hazırlanmış metal nanokümelerin ICP-OES (İndüktif Eşleşmiş Plazma-Optik Emisyon Spektrometresi), XRD (X-Işınları Kırınımı), XPS (X-Işınları Fotoelektron Spektroskopisi), TEM (Geçirimli Elektron Mikroskopu), TEM/EDX (Geçirimli Elektron Mikroskopu/Enerji Dağılımlı XIşını Spektroskopisi), ve ATR-IR (Fourier Dönüşümlü-İnfrared Spektroskopisi) gibi ileri analitik ve spektroskopik yöntemler kullanılarak tanımlanmıştır. Hazırlanan katalizörlerin hidrazin-boranın tam bozunma tepkimesinde tekrar kullanılabilirlik performansları da incelendikten sonra farklı sıcaklıklarda katalitik tepkimeler gerçekleştirilerek en etkin metal nanoküme için aktivasyon parametreleri (Ea: Aktivasyon Enerjisi; ?H*: Aktivasyon Entalpisi; ?S*: Aktivasyon Entropisi) hesaplanmıştır.
Chemical hydrides used as hydrogen storage are seen as one of the most effective ways of safely storing hydrogen in chemical compounds, transporting it efficiently and releasing hydrogen when desired. In this thesis study; Dimethyl aminborane (DMAB), which has a high hydrogen storage capacity and is the most promising among hydrogen storage materials, was used in addition to sodium borohydride (SBH), which is the most widely used chemical hydrogen storage material so far. In addition, the catalytic performances of SBH and DMAB on hydrogen production were investigated by doping Ni metal on carbon quantum dots (CQD) obtained from urea under hydrothermal and solvothermal conditions and hydrolysis of the obtained catalysts (different loading type, different NaOH effect, different catalyst amount, different borohydride concentration, temperature and reusability). In addition, in this thesis, the theoretical hydrolysis was carried out at different temperatures with molecular dynamics programme and teric calculation was performed for both NaBH4 and DMAB. It has been observed that this is in agreement with the hydrolysis results obtained in experimental studies. Finally, the prepared metal nanoclusters were analysed by ICP-OES (Inductively Coupled Plasma-Optical Emission Spectrometry), XRD (X-Ray Diffraction), XPS (X-Ray Photoelectron Spectroscopy), TEM (Transmission Electron Microscopy), The catalysts were characterised using advanced analytical and spectroscopic methods such as TEM/EDX (Transmission Electron Microscopy/Energy Dispersive X-ray Spectroscopy) and ATR-IR (Fourier Transform Infrared Spectroscopy). After examining the reusability performance of the prepared catalysts in the complete degradation reaction of hydrazine-borane, catalytic reactions were carried out at different temperatures and the activation parameters for the most efficient metal nanocluster (Ea: Activation Energy; ?H*: Activation Enthalpy; ?S*: Activation Entropy) were calculated.
Chemical hydrides used as hydrogen storage are seen as one of the most effective ways of safely storing hydrogen in chemical compounds, transporting it efficiently and releasing hydrogen when desired. In this thesis study; Dimethyl aminborane (DMAB), which has a high hydrogen storage capacity and is the most promising among hydrogen storage materials, was used in addition to sodium borohydride (SBH), which is the most widely used chemical hydrogen storage material so far. In addition, the catalytic performances of SBH and DMAB on hydrogen production were investigated by doping Ni metal on carbon quantum dots (CQD) obtained from urea under hydrothermal and solvothermal conditions and hydrolysis of the obtained catalysts (different loading type, different NaOH effect, different catalyst amount, different borohydride concentration, temperature and reusability). In addition, in this thesis, the theoretical hydrolysis was carried out at different temperatures with molecular dynamics programme and teric calculation was performed for both NaBH4 and DMAB. It has been observed that this is in agreement with the hydrolysis results obtained in experimental studies. Finally, the prepared metal nanoclusters were analysed by ICP-OES (Inductively Coupled Plasma-Optical Emission Spectrometry), XRD (X-Ray Diffraction), XPS (X-Ray Photoelectron Spectroscopy), TEM (Transmission Electron Microscopy), The catalysts were characterised using advanced analytical and spectroscopic methods such as TEM/EDX (Transmission Electron Microscopy/Energy Dispersive X-ray Spectroscopy) and ATR-IR (Fourier Transform Infrared Spectroscopy). After examining the reusability performance of the prepared catalysts in the complete degradation reaction of hydrazine-borane, catalytic reactions were carried out at different temperatures and the activation parameters for the most efficient metal nanocluster (Ea: Activation Energy; ?H*: Activation Enthalpy; ?S*: Activation Entropy) were calculated.
Açıklama
Fen Bilimleri Enstitüsü, Kimya Mühendisliği Ana Bilim Dalı, Kimya Mühendisliği Bilim Dalı
Anahtar Kelimeler
Enerji, Energy, Kimya Mühendisliği
