Steam reforming of ethanol over sol-gel-synthesized mixed oxide catalysts

---

Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Kimya Mühendisliği Bölümü, Türkiye

Tezin Onay Tarihi: 2005

Öğrenci: HAKAN ÖNDER OLCAY

Danışman: DENİZ ÜNER

Özet:

Depletion in the reserves of fossil fuels, inefficient energy production from these fuels and the negative effect of their usage on atmosphere, and thereby, on human health have accelerated researches on clean energy. Hydrogen produced from ethanol when used in fuel cells not only generates efficient energy but also creates a closed carbon cycle in nature. ZnO and Cu/ZnO catalysts are known with their superior performance in alcohol synthesis. From the principle of microkinetic reversibility they are expected to be superior catalysts for the steam reforming reaction of ethanol as well. ZnO catalysts can be modified by precious, Pd, or non-precious, Cu, metals to enhance hydrogen desorption capability, and dispersed on SiO2 for high surface areas via sol-gel technique. Steam reforming tests over ZnO catalysts revealed that they act only as ethanol dehydrogenation catalysts in the temperature range of 300-500C. Promotion with Pd or Cu decreased hydrogen selectivity due most probably to unreachable closed pores of the catalysts. Autothermal reforming tests over both ZnO/SiO2 and Co/SBA-15 catalysts, on the other hand, gave rise to the formation of several side products.