Hidrojen üretimi için katalizör olarak paladyum nanoparçacık yüklenmiş manyetik özelliğe sahip polianilin hazırlanması ve karakterizasyonu
Loading...
Date
2020
Authors
Kaya, Murat
Journal Title
Journal ISSN
Volume Title
Publisher
Open Access Color
OpenAIRE Downloads
OpenAIRE Views
Abstract
Kataliz günümüzde çok önemli bir yere sahiptir. Birçok çevre ve sürdürülebilirlikle ilgili konularda katalizör kullanımının gerekli olması sebebi ile katalizörün önemi ortaya çıkmaktadır. Metal nanoparçacıklar, sahip oldukları katalitik özellikler nedeni ile birçok araştırmacının dikkatini çekmiştir. Metal nanoparçacıkların katalizör olarak etkinliklerinin arırılması için silika ve alumina gibi destek malzemeleri üzerine yerleştirilmektedir. Bunların yanında polimer tabanlı malzemeler kararlılıkları ve üzretimlerindeki kolaylık sebebi ile son zamanlarda destek malzemesi olarak kullanılmaya başlanmıştır. Temiz ve sürdürülebilir enerji kaynakları arayışı halen devam etmektedir. Hidrojen temiz bir enerji kaynağı olarak bilinmektedir ve yakın gelecekte fosil yakıtlara olası bir alternatif olabileceği düşünülmektedir. Bu nedenle su, biyokütle, hidrokarbonlar ve kimyasal hidritler gibi hidrojen içeren birçok maddeden hidrojen eldesi ilgi odağı olmaktadır. Bu maddeler arasında, amonyak boran, yüksek stabilite ve düşük toksisite yanında yüksek oranda hidrojen (ağırlıkça% 19.6) içermesi sebebi ile de öne çıkmaktadır.Bu tezde, manyetik özelliğe sahip polianilin üzerine eklenmiş paladyum nanoparçacıkları içeren kompozit malzeme hazırlanmıştır. Bunun için öncelikle manyetik nanoparçacık içeren PANI oksidative polimerleşme yöntemi ile hazırlanmıştır. Daha sonra paladyum nanoparçacıkları sıvı içerisinde karıştırılarak yüzeye tutturulmuş ve sodium borhidrür ile indirgeme işlemi yapılarak nanoparçacık haline getirilmiştir. Hazırlanan parçacıkların katalitik aktiviteleri oda sıcaklığında amonyak borandan hidrojen eldesinde denenmiştir. Ayrıca hazırlanan malzeme ve içeriğinde bulnan diğer bileşeklerin karakterizasyonları SEM, TEM, EDX, FTIR ve ICP-OES kullanılarak yapılmıştır. Uygun koşullar belirlendikten sonra 20 mg, % 1.2 Pd nanoparçacık eklenmiş katalizörün kullanımı ile TOF değeri 220 dk-1 olarak hesaplanmıştır. Sahip olduğu manyetik özellik sayesinde katalizör reaksiyon ortamından filtreleme veya santrifüj gibi yöntemlere gereksinim duymadan harici bir mıknatıs yardımı ile kolayca ayrılmıştır. Daha sonra tekrar kullanılabilirlik çalışmasında 5 defa kullanılmış ve 5 kullanım sonunda başlangıç aktivitesinin % 95 ini koruduğu gözlemlenmiştir.
Catalysis is a crucial area today because of its importance, as 90% of chemical processes contain catalysis in at least one step in their interactions, as it addresses many environmental issues as well as issues related to sustainability. Metal nanoparticles have attracted the attention of many researchers because of their effectiveness as a catalyst because they represent a new type of catalyst through the properties it possesses. The metal nanoparticles are supported by materials such as silica and alumina to gain more good properties. Support materials such as polymeric materials have recently emerged as essential support materials in the catalyst field for their stability and ease of production. The search for clean and sustainable energy sources is still underway. Hydrogen is emerging as a source of clean energy and a possible alternative to fossil fuels soon, and many substances containing hydrogen have appeared in various proportions such as water, biomass, hydrocarbons, and chemical hydrides. Among these substances, ammonia borane is considered one of the most important of these substances that contain a high percentage of hydrogen (19.6 wt%) with high stability and low toxicity. In this thesis, palladium nanoparticles loaded polyaniline composite material (MNP-PANI-PdNPs) with a magnetic property was prepared. For this initially, magnetic nanoparticles added PANI was prepared with oxidative polymerization. After that palladium nanoparticles were loaded to the composite material by using a wet impregnation method followed with sodium borohydride reduction. The catalytic activity of the resulting particles was tested in the dehydrogenation of Ammonia borane under ambient temperature. Also, components and resulting material were characterized by using SEM, TEM, EDX, FTIR, and ICP-OES. After optimization studies, the highest TOF value was calculated as 220 min-1 for the 20 mg 1.2 % Pd (w/w) loaded catalyst. Because of the magnetic property of the catalyst, it is quickly separated from the reaction mixture using an external magnet without the need to use other methods such as filtration or centrifugation. The catalyst was reused for five consecutive reactions, the results showing that 95% of the initial activity was retained with a full hydrogen release at the end of the fifth catalyst operation.
Catalysis is a crucial area today because of its importance, as 90% of chemical processes contain catalysis in at least one step in their interactions, as it addresses many environmental issues as well as issues related to sustainability. Metal nanoparticles have attracted the attention of many researchers because of their effectiveness as a catalyst because they represent a new type of catalyst through the properties it possesses. The metal nanoparticles are supported by materials such as silica and alumina to gain more good properties. Support materials such as polymeric materials have recently emerged as essential support materials in the catalyst field for their stability and ease of production. The search for clean and sustainable energy sources is still underway. Hydrogen is emerging as a source of clean energy and a possible alternative to fossil fuels soon, and many substances containing hydrogen have appeared in various proportions such as water, biomass, hydrocarbons, and chemical hydrides. Among these substances, ammonia borane is considered one of the most important of these substances that contain a high percentage of hydrogen (19.6 wt%) with high stability and low toxicity. In this thesis, palladium nanoparticles loaded polyaniline composite material (MNP-PANI-PdNPs) with a magnetic property was prepared. For this initially, magnetic nanoparticles added PANI was prepared with oxidative polymerization. After that palladium nanoparticles were loaded to the composite material by using a wet impregnation method followed with sodium borohydride reduction. The catalytic activity of the resulting particles was tested in the dehydrogenation of Ammonia borane under ambient temperature. Also, components and resulting material were characterized by using SEM, TEM, EDX, FTIR, and ICP-OES. After optimization studies, the highest TOF value was calculated as 220 min-1 for the 20 mg 1.2 % Pd (w/w) loaded catalyst. Because of the magnetic property of the catalyst, it is quickly separated from the reaction mixture using an external magnet without the need to use other methods such as filtration or centrifugation. The catalyst was reused for five consecutive reactions, the results showing that 95% of the initial activity was retained with a full hydrogen release at the end of the fifth catalyst operation.
Description
Keywords
Kimya, Kimya Mühendisliği, Chemistry, Dehidrojenasyon, Chemical Engineering, Dehydrogenaration, Metal nanopartiküller, Metal nanoparticles
Turkish CoHE Thesis Center URL
Fields of Science
Citation
WoS Q
Scopus Q
Source
Volume
Issue
Start Page
0
End Page
60