COUPLING DIFFUSE-REFLECTANCE FOURIER-TRANSFORM INFRARED SPECTROMETRY WITH GAS-CHROMATOGRAPHY (DRIFT-GC) - A HIGH-PERFORMANCE COUPLED TECHNIQUE FOR CATALYST CHARACTERIZATION

The combination of diffuse reflectance Fourier transform infrared spec trometry and gas chromatography (DRIFT-GC) was applied to the thermal characterization of solid materials. In the instrumental design, parti cular attention was devoted to minimizing the time delays between the responses of the DRIFT and the GC detectors. It was thus possible to c orrelate the changes in the IR spectrum with the composition of the ga s phase as a function of the linearly increasing temperature. Manganes e carbonyl [Mn-2(CO)(10)] dispersed on a porous zeolitic matrix was ch osen as reference material to test and validate the analytical methodo logy, since it combines a simple and predictable decomposition chemist ry with a wed defined infrared spectrum. Improved insights into the th ermal characterization of solid materials and catalysts were achieved with this coupled technique. All gas-phase processes, which are genera lly hidden to IR investigations, can be revealed and studied. Moreover , the 'fingerprinting' capabilities of IR spectrometry allow the decon volution of the elementary processes of gas evolution, greatly improvi ng the resolution of temperature programmed techniques.