Frame Catalysts of Al2O3–ZrO2–CeO2 System

Resumo

Xerogels and powders of Al₂O₃–ZrO₂–CeO₂ systems with different pore structure and matrixes of ZrO₂ and Al₂O₃ are obtained. The specific surface area of xerogels with ZrO₂ matrix and Al₂O₃ matrix exceeds 200 and 90 m²/g, respectively. After calcinations at 950°C, the powders retain nanoscale, with the size of individual particles ranging from 70 to 28 nm. The main crystalline phase in these powders is a solid solution of tetragonal zirconia. Total ethanol conversion of xerogels with ZrO₂ and Al₂O₃ matrixes has similar values. Selectivity to ethylene conversion is about 50% and does not depend on calcination temperature. For samples with an Al₂O₃ matrix, ethylene selectivity of 50% was reached after heating at 950°C. It is shown that the catalytic activity of ethanol conversion reaction is higher for samples with a more crystallized phase based on solid solution of tetragonal zirconia, namely, for samples with the ZrO₂ matrix calcined at 950°C.