A gas chromatography/mass spectrometry study of the conversion of alicyclic alcohols on membrane-type catalysts using a pulse microreactor implanted into a gas chromatograph injector

A pulse microreactor implanted directly into a gas chromatograph injector combined with a mass spectrometer has been proposed for monitoring the activity of heterogeneous catalysts. The microreactor was made of a standard commercial liner for a particular gas chromatograph and contained a catalytic bed. A heated injector oven was used simultaneously for heating the catalytic region, rapid evaporation of the substrate, and pulsed introduction of reaction products into a chromatographic column. The temperature of the oven could be varied in the range 200–300°C. The method ensures the detailed description of the qualitative composition of the reaction products. The potential of the proposed microreaction system was demonstrated in the study of membrane-type catalysts (nanodiamonds modified by Pt–Ru and Pt–Ni and also catalytic phosphate systems with NASICON structure) in reactions of cyclohexanol, cyclopentanol, and cyclobutanol. The studied heterogeneous catalysts can be divided in two groups. One group (based on nanodiamonds) promotes dehydrogenation reactions. The NASICON catalytic group catalyzes dehydration reactions with the formation of cycloalkenes and dicycloalkyl ethers.