Akademik Veri Yönetim Sistemi
Tezin Türü: Yüksek Lisans
Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Kimya Mühendisliği Bölümü, Türkiye
Tezin Onay Tarihi: 2004
Tezin Dili: İngilizce
Öğrenci: Murat Üner
Danışman: DENİZ ÜNER
Özet:In this study, the structure sensitivity of hydrogen, oxygen and carbon monoxide adsorption was investigated by changing the metal particle size of Pt/Al2O3 catalysts. 2 % Pt/Al2O3 catalysts were prepared by incipient wetness method; the particle size of the catalysts was manipulated by calcining at different temperatures. The dispersion values for the catalysts calcined in air at 683K, 773K and 823K were measured as 0.62, 0.20 and 0.03 respectively. The differential heats of adsorption of hydrogen, carbon monoxide and oxygen were measured using a SETARAM C80 Tian-Calvet calorimeter. No structure dependency was observed for hydrogen, carbon monoxide or oxygen initial heats of adsorption. The adsorbate:metal stoichiometries at saturation systematically decreased with increasing particle size. Hydrogen chemisorption sites with low and intermediate heats were lost when the particle size increased. On the other hand, oxygen and carbon monoxide initial heats and adsorption site energy distributions did not change appreciably with the metal particle size.