Publication: Metanolün seçimli oksidasyonunda demir (III) molibdatın katalizör etkisinin analitik yönden incelenmesi
Abstract
METANOLÜN SEÇİMLİ OKSİDASYONUNDA DEMİR (III) MOLİBDAT’IN KATALİZÖR ETKİSİNİN ANALİTİK YÖNDEN İNCELENMESİ Alifatik aldehit grubunun birinci sırasında yer alan formaldehit, H2C=O, sahip olduğu yüksek kimyasal aktivite sayesinde birçok alanda kullanılan oldukça önemli bir endüstriyel kimyasaldır. İnsanoğlunun sürekli değişen ve çoğalan gereksinimleri kimyasal endüstride kullanılan formaldehit tüketiminide fazlasıyla artırmıştır. Bu nedenle son on yıldır formaldehit üretimi ve mevcut verimini artırmak için bir çok bilimsel çalışma yapılmaktadır. Günümüz dünyasında formaldehit üretimi, metanolü hammadde olarak kullanan heterojen katalitik proseslere dayanmaktadır. Bu proseslerde kullanılan çeşitli katalizörler vardır. En yüksek formaldehit verimini ve metanol dönüşümünü Mo açısından zengin demir(ІІІ) molibdat katalizörleri göstermektedir. Yapılan tez çalışmasında, Mo oranı fazla olan demir(ІІІ) molibdat katalizörlerinin yüzey faz bileşenleri ve katalitik özellikleri göz önünde bulundurularak, daha yüksek formaldehit verimi sağlayabilicek alternatif demir(ІІІ) molibdat türevi katalizörler araştırıldı. Yüzey fazının Mo açısından zengin olabilmesi için ‘The incipient wetness impregnation’ metodu kullanılarak demir oksit üzerine çeşitli oranlarda MoO3 (≥1ML) katmanları kaplandı. PFR (Sekmeli Akış Rektör) çalışma türlerinden ikisi olan; TPPFR (Sıcaklık Programlamalı Sekmeli Akış Rektör Çalışması) ve TPD (Sıcaklık Programlamalı Desorpsiyon Çalışması) kullanılarak ürün seçicilikleri ve metanol dönüşümleri karşılaştırıldı. En yüksek formaldehit verimi sağlayan demir(ІІІ) molibdat katalizörü ve deney aşamaları belirlendi. Elde edilen sonuçlara göre en yüksek formaldehit seçiciliği (~%100), 4000C’de 90 dakika boyunca kalsine edilen 5.9 ML MoO3/ Fe2O3 katalizör örneği göstermiş ve yeni bir alernatif heterojen katalizör varlığı ortaya konmuştur.
ANALYTICAL RESEARCH ON THE CATALYTICAL EFFECT OF IRON (III) MOLYBDATE OVER THE SELECTIVE OXIDATION OF METHANOL Formaldehyde, H2C=O, is a reactive molecule, the first series of aliphatic aldehydes, due to its high chemical reactivity, formaldehyde is one of the most important and irreplaceable industrial chemical. As to the considerable relevance of formaldehyde in chemical industry wherewith growing human population around the world, a large volume of study have been focusing its production in the last decades. Nowadays all of the world production of formaldehyde is based on heterogeneous catalytic processes using methanol as a feedstock. There are few different catalysts which in use but iron(ІІІ) molybdate catalysts have the highest formaldehyde yield and methanol conversion. Therefore iron(ІІІ) molybdate catalyst has become quite requirement chemical on concerning not only its high selectivity to formaldehyde but also its catalytic properties. In this study, alternative iron(ІІІ) molybdate catalyst derivatives obtained by doping MoO3 monolayers (≥1ML) on the surface of iron oxide to obtain Mo rich phases which lead high formaldehyde yield. The catalysts were prepared by ‘The incipient wetness impregnation’ on to synthesised iron oxide. PFR (Pulsed Flow Reactor) and TPD (Temperature Programmed Desorption) techniques were used to analyze formaldehyde selectivity and methanol conversion. As a result of that iron(ІІІ) molybdate catalyst which has the highest formaldehyde yield and its experimental stages were determined. The highest (~100%) formaldehyde selectivity and methanol conversion was obtained by the use of 5.9 ML MoO3/ Fe2O3 catalyst which calcined at 4000C for 90 minutes.
ANALYTICAL RESEARCH ON THE CATALYTICAL EFFECT OF IRON (III) MOLYBDATE OVER THE SELECTIVE OXIDATION OF METHANOL Formaldehyde, H2C=O, is a reactive molecule, the first series of aliphatic aldehydes, due to its high chemical reactivity, formaldehyde is one of the most important and irreplaceable industrial chemical. As to the considerable relevance of formaldehyde in chemical industry wherewith growing human population around the world, a large volume of study have been focusing its production in the last decades. Nowadays all of the world production of formaldehyde is based on heterogeneous catalytic processes using methanol as a feedstock. There are few different catalysts which in use but iron(ІІІ) molybdate catalysts have the highest formaldehyde yield and methanol conversion. Therefore iron(ІІІ) molybdate catalyst has become quite requirement chemical on concerning not only its high selectivity to formaldehyde but also its catalytic properties. In this study, alternative iron(ІІІ) molybdate catalyst derivatives obtained by doping MoO3 monolayers (≥1ML) on the surface of iron oxide to obtain Mo rich phases which lead high formaldehyde yield. The catalysts were prepared by ‘The incipient wetness impregnation’ on to synthesised iron oxide. PFR (Pulsed Flow Reactor) and TPD (Temperature Programmed Desorption) techniques were used to analyze formaldehyde selectivity and methanol conversion. As a result of that iron(ІІІ) molybdate catalyst which has the highest formaldehyde yield and its experimental stages were determined. The highest (~100%) formaldehyde selectivity and methanol conversion was obtained by the use of 5.9 ML MoO3/ Fe2O3 catalyst which calcined at 4000C for 90 minutes.