Multivariate correlation and prediction of the synthesis of vanadium substituted mesoporous molecular sieves

Vanadium substituted mesoporous molecular sieves (V-MCM-41) were prepared following a synthesis procedure developed in our laboratory [J. Phys. Chem. B 106 (2002) 8437]. N₂ adsorption and X-ray diffraction experimental results show that our samples have a highly ordered hexagonal structure and fairly good stability. X-ray absorption and UV-vis spectra provide strong evidence that most vanadium ions are incorporated into the framework of siliceous MCM-41. The most important variable properties are the structural order, pore diameter, and vanadium loading which can be controlled easily by changing synthesis variables in such a way that collapse of the V-MCM-41 structure does not occur. A more quantitative model was built to correlate the structure, pore size, and vanadium content with the main synthesis variables and their cross terms. Modeling results show that our models are reasonably good at predicting the structure and pore diameter, it also can predict vanadium loading content well with longer alkyl chain length.