Chemical Engineering and Catalysis

Catalysis and Zeolites

Zeolites are the most important heterogeneous catalysts with numerous large-scale applications including cracking, petrochemistry, fine chemical synthesis, and environmental protection. This themed issue evidences the significant impact of zeolites in catalysis, new trends in catalytic applications of zeolites and, in particular, their potential in catalysis. Zeolitesis used as catalysts in petrochemical industries for cracking of hydrocarbons and isomerization. An important zeolite catalyst used in the petroleum industry is ZSM-5. It converts alcohols directly into gasoline (petrol) by dehydrating them to give a mixture of hydrocarbons. Electron microscopic investigations of zeolites are reviewed. Scanning electron microscopy can show the appearance of zeolite crystals, e.g. their sizes and morphologies, and can also be used to look into the cores of crystals, revealing any abnormal microstructures, which often help us to elucidate actual crystal growth mechanisms. High resolution transmission electron microscopy is a powerful tool to directly image many pore systems and local defects in zeolites.