Time-resolved C-13 MAS NMR investigation of chemical reactions: the MTG process

Sample heating with a laser beam facilitates time-dependent magic angle spi nning (MAS) NMR spectroscopy of high-temperature reactions in situ. The met hanol-to-gasoline conversion (MTG process) was monitored by C-13 MAS NMR sp ectroscopy using the stop-and-go method in addition to the continuous heati ng of sealed samples. It was found that effective alkane formation is force d by interrupted laser heating. With a decrease of the dimethyl ether conce ntration a constant concentration of methanol was observed under both conti nuous and interrupted heating conditions. Copyright (C) 1999 John Wiley & S ons, Ltd.