Microwave Reaction Enhancement: The Rapid Synthesis of SAPO-11 Molecular Sieves

The effect of microwave and conventional heating methods on the nucleation and growth of SAPO-11 molecular sieve was investigated. Microwave synthesis enhances both the nucleation and growth of SAPO-11. The rate of heating primarily influences the nucleation time for both microwave and conventional heating. A more uniform morphology and narrower size distribution are formed using microwave heating compared to conventional. This suggests that rapid and even nucleation is the enhancement mechanism. Crystallization by conventional heating can be accelerated by immersion in the pre-heated fluid due to the faster heating rate and improved thermal conduction. Microwave synthesis of SAPO-11 occurs in minutes and, thus, significant energy savings can be realized compared to the hours required for conventional synthesis.