Electrochemical production of transition metal-based electrocatalysts for water splitting
[ X ]
Tarih
2022
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Adana Alparslan Türkeş Bilim ve Teknoloji Üniversitesi
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Dünya nüfusunun, teknolojik gelişmelerin ve endüstriyel faaliyetlerin giderek artmasından dolayı enerji kaynakları gün geçtikçe azalmaktadır. Özellikle, yenilenemeyen enerji kaynaklarının (kömür, petrol, doğal gaz, vb.) kullanımı sera gazı, küresel ısınma gibi etkilerle dünyaya ciddi derecede zarar vermektedir. Dünya üzerindeki bu olumsuz etkileri gören ülkeler, gelecek nesillere refah bir yaşam alanı bırakmak için enerjinin ve insanlığın sürdürülebilirliğini sağlamak adına yenilenebilir enerji sektörlerini keşfetmeye başlamışlardır. Bu amaca yönelik; yenilenebilir kaynaklar destekli elektroliz yoluyla elektrokimyasal hidrojen üretimi uygun bir çözüm olabilir. Bu sebeple, yenilenebilir enerji kaynakları, dünyanın ve Türkiye'nin geleceği için çok önemlidir. Türkiye petrol ve kömür gibi birçok yenilenemeyen enerji kaynağını ithal etmektedir. Ne yazık ki ithal edilen enerji kaynakları Türkiye'nin ekonomisini ciddi şekilde etkilemektedir. Ülkemizin coğrafi konumu yenilenebilir enerji üretimine çok uygun olup, özellikle jeotermal, güneş ve rüzgar enerjisi açısından oldukça verimli bir konumdadır. Yenilenebilir enerjilere yatırım yaparak ülkemizin ekonomi seviyesini daha yukarıya taşıyabiliriz. Bu bağlamda sıfır karbon emisyonu, yüksek enerji potansiyeli ve son dönemlerde araştırmacıların ciddi şekilde ilgisini toplamış olan "hidrojen enerjisi" dikkat çekmektedir. Hidrojen gazı eldesi için birçok yöntem kullanılmasına rağmen avantajları sebebiyle alkali elektroliz yöntemi tercih edilmektedir. Bu yöntemde elektrot seçimi çok önemlidir. Bilindiği üzere, platin (Pt) esaslı malzemelerin düşük aşırı gerilimleri ve yüksek akım yoğunlukları nedeniyle en verimli elektrokatalizörler olarak Pt ihtiva eden malzemeler kullanılmaktadır. Fakat Pt'nin maliyetinin yüksek olması, kullanımını ciddi oranda kısıtlamaktadır. Bu çalışmada rüzgar türbininden üretilen elektrik enerjisinden faydanılarak hidrojen gazı üretilmiştir. Üretim sırasında çeşitli elektrotların anot ve katot pozisyonlarındaki kombinasyonu deneysel ortamda gözlemlenip hidrojen gazı üretimi için en uygun elektroliz hücresi tespit edilmiştir. Platin (Pt), paslanmaz çelik (SS), grafit (G), ve bakır (Cu) elektrotlar, alkali elektroliz hücresinde anot olarak kullanılmıştır. Grafit ise yüksek elektrik iletkenliği, düşük maliyeti ve korozyon direncinden (elektrik kesintisi durumunda) dolayı katot elektrotu olarak tercih edilmiştir. Ayrıca grafit elektrot, galvanostatik yöntemle nikel (Ni), kobalt (Co) ve bakır (Cu) ile modifiye edilmiştir. Üçlü kaplama kalınlığı yaklaşık 10 µm dir. Elektrot yüzeyi, taramalı elektron mikroskobu ve enerji dağılımlı X-ışını spektroskopisi ile karakterize edilmiştir. Alkali elektroliz işlemi, 15 dakika boyunca iki elektrot sistemi ile gerçekleştirilmiştir, çeşitli potansiyeller için üretilen hidrojen gazı (H2(g)) hacimleri belirlenmiştir. Deneysel çalışmaların sonucuna göre; Pt-G (Hücre-1), SS-G (Hücre-2), G-G (Hücre-3), Cu-G (Hücre-4), SS-G/NiCoCu (Hücre-5), G-G/NiCoCu (Hücre-6), Cu-G/NiCoCu (Hücre-7) 'nin 3 V'da 15 dakika sonundaki hidrojen gazı üretimleri sırasıyla 15 mL; 11,13 mL; 9,30 mL; 8,71 mL; 13,12 mL; 10,10 mL; 10,97 mL dir.
Due to increasing world population, technological developments and industrial activities, energy resources are decreasing day by day. In particular, the use of non-renewable energy resources (coal, oil, natural gas, etc.) seriously damages the world with effects such as greenhouse gas and global warming. Countries that see these negative effects on the world have started to explore renewable energy sectors in order to ensure the sustainability of energy and humanity in order to leave a prosperous living space for future generations. For this purpose; electrochemical hydrogen production by renewable sources assisted electrolysis may be a viable solution. For this reason, renewable energy sources are very important for the future of the world and also Turkey. Turkey imports many non-renewable energy resources such as oil and natural gas. Unfortunately, imported energy resources seriously affect Turkey's economy. The geographical location of our country is very suitable for renewable energy production, and it is in a very efficient position especially in terms of geothermal, solar and wind energy. We can raise the economy level of our country by investing in renewable energies. In this context, zero carbon emissions, high energy potential and "hydrogen energy", which have recently attracted the attention of researchers, draw attention. Although many methods are used to obtain hydrogen gas, alkaline electrolysis method is preferred due to its advantages. Electrode selection is very important in this method. As it is known, materials containing platinum (Pt) are used as the most efficient electrocatalysts due to the low overvoltages and high current densities of Pt based materials. However, the high cost of Pt greatly restricts its usage. In this study, hydrogen gas was produced by utilizing the electrical energy produced from the wind turbine. During the production, the combination of various electrodes in the anode and cathode positions were observed in the experimental environment and the most convenient electrolysis cell for hydrogen gas production was determined. Platinum (Pt), stainless steel (SS), graphite (G), and copper (Cu) electrodes were used as anodes in the alkaline electrolysis cell. Graphite, was preferred as the cathode electrode due to its high electrical conductivity, low cost and corrosion resistance (in case of power cut). In addition, the G electrode was modified with nickel (Ni), cobalt (Co) and copper (Cu) by galvanostatic method. The ternary coating thickness was approximately 10 µm. The electrode surface was characterized by scanning electron microscopy and energy dispersive X-ray spectroscopy. The alkaline electrolysis process was carried out with two electrode systems for 15 minutes, the volumes of hydrogen gas (H2(g)) produced for various potentials were determined. According to the experimental results, at each 3 V for 15 minutes of electrolysis time, the produced H2(g) various were; 15 mL; 11.13 mL; 9.30 mL; 8.71 mL; 13.12 mL; 10.10 mL; 10.97 mL for Pt-G (Cell-1), SS-G (Cell-2), G-G (Cell-3), Cu-G (Cell-4), SS-G/NiCoCu (Cell-5), GG/NiCoCu (Cell-6), Cu-G/NiCoCu (Cell-7), respectively.
Due to increasing world population, technological developments and industrial activities, energy resources are decreasing day by day. In particular, the use of non-renewable energy resources (coal, oil, natural gas, etc.) seriously damages the world with effects such as greenhouse gas and global warming. Countries that see these negative effects on the world have started to explore renewable energy sectors in order to ensure the sustainability of energy and humanity in order to leave a prosperous living space for future generations. For this purpose; electrochemical hydrogen production by renewable sources assisted electrolysis may be a viable solution. For this reason, renewable energy sources are very important for the future of the world and also Turkey. Turkey imports many non-renewable energy resources such as oil and natural gas. Unfortunately, imported energy resources seriously affect Turkey's economy. The geographical location of our country is very suitable for renewable energy production, and it is in a very efficient position especially in terms of geothermal, solar and wind energy. We can raise the economy level of our country by investing in renewable energies. In this context, zero carbon emissions, high energy potential and "hydrogen energy", which have recently attracted the attention of researchers, draw attention. Although many methods are used to obtain hydrogen gas, alkaline electrolysis method is preferred due to its advantages. Electrode selection is very important in this method. As it is known, materials containing platinum (Pt) are used as the most efficient electrocatalysts due to the low overvoltages and high current densities of Pt based materials. However, the high cost of Pt greatly restricts its usage. In this study, hydrogen gas was produced by utilizing the electrical energy produced from the wind turbine. During the production, the combination of various electrodes in the anode and cathode positions were observed in the experimental environment and the most convenient electrolysis cell for hydrogen gas production was determined. Platinum (Pt), stainless steel (SS), graphite (G), and copper (Cu) electrodes were used as anodes in the alkaline electrolysis cell. Graphite, was preferred as the cathode electrode due to its high electrical conductivity, low cost and corrosion resistance (in case of power cut). In addition, the G electrode was modified with nickel (Ni), cobalt (Co) and copper (Cu) by galvanostatic method. The ternary coating thickness was approximately 10 µm. The electrode surface was characterized by scanning electron microscopy and energy dispersive X-ray spectroscopy. The alkaline electrolysis process was carried out with two electrode systems for 15 minutes, the volumes of hydrogen gas (H2(g)) produced for various potentials were determined. According to the experimental results, at each 3 V for 15 minutes of electrolysis time, the produced H2(g) various were; 15 mL; 11.13 mL; 9.30 mL; 8.71 mL; 13.12 mL; 10.10 mL; 10.97 mL for Pt-G (Cell-1), SS-G (Cell-2), G-G (Cell-3), Cu-G (Cell-4), SS-G/NiCoCu (Cell-5), GG/NiCoCu (Cell-6), Cu-G/NiCoCu (Cell-7), respectively.
Açıklama
Fen Bilimleri Enstitüsü, Elektrik-Elektronik Mühendisliği Ana Bilim Dalı
Anahtar Kelimeler
Elektrik ve Elektronik Mühendisliği, Electrical and Electronics Engineering
