Dağdağan çekirdeği (Celtis australis) destekli katalizörlerin hidrojen üretme ve enerji depolama kapasitelerinin araştırılması
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Tarih
2024
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Siirt Üniversitesi
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Bu çalışmanın amacı, organik atık dağdağan çekirdeğinden (DAN) üretilen düşük maliyetli mikrodalga destekli aktif karbonun, NaBH4'ün metanoliz reaksiyonunda etkin bir katalizör ve süperkapasitörlerde yüksek performanslı bir elektrot malzemesi olarak kullanım potansiyelini araştırmaktır. Bu bağlamda, aktif karbonun sentezi için çeşitli parametreler optimize edilmiştir. Bu parametreler arasında kimyasal aktivatör türü (KOH, H2SO4, H3PO4, K2CO3, CH3COOH), emdirme oranı (1:0,025, 1:0,05, 1:1, 1:2, 1:3), emdirme süresi (12s, 24s, 36s, 48s), mikrodalga gücü (250W, 500W, 750W, 1000W) ve mikrodalga süresi (5dk, 10dk, 15dk, 20dk) yer almaktadır. Optimum katalizör, H2SO4 kimyasal aktivatörünün 1:1 oranında kullanıldığı, 24 saat emdirme süresi uygulanan, 500 watt mikrodalga gücü ile 10 dk mikrodalga süresinde elde edilerek DAN-S-kat olarak adlandırılmıştır. Hazırlanan katalizörün etkinliğini ve performansını optimize etmek amacıyla, reaksiyon sıcaklığı, NaBH4 konsantrasyonu, katalizör miktarı ve tekrar kullanılabilirlik gibi çeşitli parametreler detaylı bir şekilde incelenmiştir. DAN-S katalizörü ile 30 °C'de gerçekleştirilen %2,5 NaBH4 metanoliz reaksiyonundan elde edilen maksimum hidrojen üretim hızı (HGR) 8379 mL/dk.gkat olarak tespit edilmiştir. Ayrıca, bu katalizörün aktivasyon enerjisi 42,84 kJ/mol olarak hesaplanmıştır. DAN-S katalizörün karakterizasyonu için SEM-EDX, BET, XRD ve FTIR analiz teknikleri kullanılmıştır. Katalitik etkinliği en yüksek katalizörün enerji depolama özelliklerini değerlendirmek amacıyla döngüsel voltametri, galvanostatik şarj-deşarj ve elektrokimyasal empedans spektroskopisi testleri gerçekleştirilmiştir. Bu testler sonucunda, DAN-S katalizörünün 0,25 A/g akım yoğunluğunda 73,19 F/g kapasitans değeri, 2,88 Wh/kg enerji yoğunluğu ve 418,06 W/kg güç yoğunluğu sağladığı hesaplanmıştır.
The objective of this study was to investigate the potential of using low-cost, microwave-assisted activated carbon produced from organic waste, specifically dagdagan seeds (DAN), as an efficient catalyst for the methanolysis reaction of NaBH4 and as a high-performance electrode material for supercapacitors. In this context, various parameters were optimized for the synthesis of activated carbon, including the type of chemical activator (KOH, H2SO4, H3PO4, K2CO3, CH3COOH), impregnation ratio (1:0,025, 1:0,05, 1:1, 1:2, 1:3), impregnation time (12s, 24s, 36s, 48s), microwave power (250W, 500W, 750W, 1000W), and microwave duration (5 min, 10 min, 15 min, 20 min). The optimal catalyst, designated as DAN-S, was synthesized using H2SO4 as the chemical activator in a 1:1 ratio, with a 24-hour impregnation time, 500-watt microwave power, and a 10-minute microwave duration. To optimize the effectiveness and performance of the prepared catalyst, various parameters such as reaction temperature, NaBH4 concentration, catalyst amount, and reusability were thoroughly investigated. The maximum hydrogen production rate (HGR) from the 2,5% NaBH4 methanolysis reaction conducted at 30 °C with the DAN-S catalyst was determined to be 8379 mL/min/g-cat. Additionally, the activation energy of this catalyst was calculated to be 42,84 kJ/mol. Characterization of the DAN-S catalyst was performed using SEM-EDX, BET, XRD, and FTIR analysis techniques. Performance tests, including cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy, were carried out to evaluate the energy storage properties of the most catalytically active catalyst. The results demonstrated that the DAN-S catalyst achieved a capacitance of 73,19 F/g at a current density of 0,25 A/g, an energy density of 2,88 Wh/kg, and a power density of 418,06 W/kg.
The objective of this study was to investigate the potential of using low-cost, microwave-assisted activated carbon produced from organic waste, specifically dagdagan seeds (DAN), as an efficient catalyst for the methanolysis reaction of NaBH4 and as a high-performance electrode material for supercapacitors. In this context, various parameters were optimized for the synthesis of activated carbon, including the type of chemical activator (KOH, H2SO4, H3PO4, K2CO3, CH3COOH), impregnation ratio (1:0,025, 1:0,05, 1:1, 1:2, 1:3), impregnation time (12s, 24s, 36s, 48s), microwave power (250W, 500W, 750W, 1000W), and microwave duration (5 min, 10 min, 15 min, 20 min). The optimal catalyst, designated as DAN-S, was synthesized using H2SO4 as the chemical activator in a 1:1 ratio, with a 24-hour impregnation time, 500-watt microwave power, and a 10-minute microwave duration. To optimize the effectiveness and performance of the prepared catalyst, various parameters such as reaction temperature, NaBH4 concentration, catalyst amount, and reusability were thoroughly investigated. The maximum hydrogen production rate (HGR) from the 2,5% NaBH4 methanolysis reaction conducted at 30 °C with the DAN-S catalyst was determined to be 8379 mL/min/g-cat. Additionally, the activation energy of this catalyst was calculated to be 42,84 kJ/mol. Characterization of the DAN-S catalyst was performed using SEM-EDX, BET, XRD, and FTIR analysis techniques. Performance tests, including cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy, were carried out to evaluate the energy storage properties of the most catalytically active catalyst. The results demonstrated that the DAN-S catalyst achieved a capacitance of 73,19 F/g at a current density of 0,25 A/g, an energy density of 2,88 Wh/kg, and a power density of 418,06 W/kg.
Açıklama
Fen Bilimleri Enstitüsü, Kimya Mühendisliği Ana Bilim Dalı
Anahtar Kelimeler
Kimya Mühendisliği, Chemical Engineering
