HIGH THERMAL-STABILITY OF SAPO-40 IN N-OCTANE CRACKING

SAPO-40 is a highly active and thermally stable cracking catalyst. A c omparison with LZY-82 and SAPO-37 in n-octane cracking shows that afte r pretreatment at around 800 degrees C and above it is more active tha n LZY-82. Upon pretreatment at increasing temperature its hydrogen tra nsfer activity decreases while that of SAPO-37 increases. The results are related to the unusually thin SAPO-40 crystals and to the distribu tion of silicon atoms in the framework.