Demir Yüklemenin MCM-41 ve MCM-48 Mezo Gözenekli Yapıların Fizikokimyasal Özellikleri Üzerine Etkisi

Öz

Bu çalışmada MCM-41 ve MCM-48 mezogözenekli yapılar sentezlenmiş ve yapılarına değişik Fe/Si oranlarında yaş emdirme ile demir yüklenmiştir. X-ışını kırınım desenleri tek boyutlu düzenli silika matriksi ile MCM-41 ve üç boyutlu silika matriksi ile MCM-48 yapıların oluşumunu göstermiştir.  Düzenli mezo gözenek yapısını sergileyen ilk pik, her iki yapıda 2θ değerinin 2.6^o değerinin altında keskin bir şekilde gözlenmiş ve demir emdirme ile pik şiddetinde azalma meydana gelmiştir. Amorf silika duvar varlığı MCM-41 yapı için 10-40^o arasında gözlenirken MCM-48 için daha geniş bir aralıkta sergilenmiştir. Demirin yapıya oksit formunda yüklendiği X-ışını kırınım desenleri ile belirlenirken, enerji dağılımlı X-ışınları spektroskopisi (EDS) demir yükleme başarısının % 95 değerlerine ulaştığı göstermektedir. Demir yüklemesi, MCM-41 ve MCM-48 için sırasıyla 1073 ve 1200 m²/g olarak belirlenen yüzey alan değerlerinde % 25’e varan azalmaya neden olmuştur. Taramalı elektron microskobu nispeten homojen parçacık boyutlarının oluşumunu ve emdirme işlemi ile kümeleşmenin meydana geldiğini, MAP görüntüsü ise demir bileşiklerinin silika duvar üzerinde homojen dağıldığının göstermiştir.

Anahtar Kelimeler: mezo gözenek, düzenli yapı, yaş emdirme, yapısal özellikler, kimyasal özellik

Kaynakça

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