Understanding the mechanism of large-scale template elimination during calcination of Mcm-41

An in-depth study of the thermal detemplation of the MCM-41 was carried out in a designed setup running with a high catalyst loading. Mapping the temperature along the catalyst bed during detemplation provides an understanding of the heat transfer phenomena involved under (an)aerobic conditions. Comparison between the results obtained at low (TG/DTA study) and high sample loadings (fixed-bed reactor) suggest that oxygen presence modifies the detemplation mechanism and high flows increase the local temperature in the bed due to the exothermic nature of hydrocarbon oxidation. Thermal cracking products detected during calcination may be considered a benchmark to deduce the local conditions in the catalyst bed. Despite the differences in detemplation processes, both environments lead to solids with similar structural properties. The use of advanced analytical techniques, such as 2D GC, led to the proposal of a detailed reaction scheme for the detemplation step.