Quantitative spectrokinetic analysis of gas/solid reactions using a micro-reactor with simultaneous detection by DRIFT and mass spectrometry

AGUIRRE, ALEJO; COLLINS, SEBASTIAN

Congreso; VI International Congress on Operando Spectroscopy; 2018

Understanding of reaction mechanisms and structure-activity relationships under working ?Operando- conditions is of central importance to perform a rational design of new and optimized catalytic systems. Diffuse reflectance infrared spectroscopy -DRIFT- is a powerful technique to monitor the reaction intermediates at the gas(reactant)/solid(catalyst) interfase. However, the most popular design of DRIFT cells features a (heated) cup where the catalyst powder is placed and the gas feed is, in the best situation, forced to flow though the catalyst bed. This design has some problems that can hamper the correct correlation between intermediates (IR signals) and gas phase concentration (e.g. CG or MS signals): i) temperature gradient in the catalyst bed, ii) IR "sensing" at the top/beginning of the catalyst bed, iii) possibility of by-pass of the gases, iv) large difference of temperature between the catalytic bed and the ?cup?, (v) large volume to exchange in transient studies. In this work, the design, modelling and use of a DRIFT cell that features a plug-flow micro-reactor, coupled with mass spectrometry to perform Operando and transient studies in a quantitative manner is described.