A Versatile Ambient‐to‐High‐Pressure Reaction Transmission Cell for in situ/operando Infrared Spectroscopic Investigations

Abstract

Design and applications of an in-house developed high pressure/high temperature transmission FTIR reaction cell are presented. By coupling with a mass spectrometer online analysis of product formation is possible enabling operando FTIR spectroscopic studies. The cell, made of stainless-steel, has been designed to be operable at pressures up to 30 bar and temperatures between 22°C and 300°C. Long-time tests, with no signs of damage of the cell and windows have been conducted at 15 bar and 250°C. The performance of the cell was tested by studying three types of CO 2 hydrogenation reactions (CO 2 Fischer-Tropsch synthesis, CO 2 methanation, CO 2 conversion to dimethyl ether) on selected catalyst systems by varying temperature and pressure. The operando spectroscopic measurements revealed reliable data which reflect the same trends as found by respective catalytic tests.

Operando DRIFT and In situ Raman Spectroscopic Studies on Aspects of CO2 Fischer‐Tropsch Synthesis Catalyzed by Bulk Iron Oxide‐Based Catalysts

“…The CO 2 adsorption ability of Fe-300-H 2 is expected to be weak as indicated by previous studies, which also failed to detect adsorbed carbonate species on magnetite under a variety of conditions. [29,34,37,47] When H 2 was dosed into the reaction cell, only CH 4 and water was formed relatively quickly, by probably direct hydrogenation of residual CO 2 in the cell. [5] Carbon monoxide is not observed.…”

“…[26][27][28] Infrared spectroscopic studies on iron oxide catalysts during exposure to CO 2 , CO and H 2 have been performed. [24,[29][30][31][32][33][34][35][36][37] While many of these studies were carried out to identify the surface species on Fe 2 O 3 , comparatively little information can be found about observable adsorbate species under relevant conditions for CO 2 -FT.…”

“…Various Raman spectroscopic investigations on the dynamic phase transformations of iron oxide catalysts in the context of Fischer‐Tropsch synthesis have been published [26–28] . Infrared spectroscopic studies on iron oxide catalysts during exposure to CO 2 , CO and H 2 have been performed [24,29–37] . While many of these studies were carried out to identify the surface species on Fe 2 O 3 , comparatively little information can be found about observable adsorbate species under relevant conditions for CO 2 ‐FT.…”