In situ XAFS analysis system for high-pressure catalytic reactions and itsapplication to CO2 hydrogenation over a Rh/Y-zeolite catalyst

An in-situ XAFS cell was developed and used for the structural analysis of a Rh ion-exchanged zeolite catalyst during high-pressure hydrogenation of c arbon dioxide. The in-situ cell enabled analyses of the catalyst structures that changed with the reaction atmosphere and elapsed time; the peak assig ned to Rh-O scattering changed to that assigned to Rh-Rh scattering at 404 K during the pretreatment by hydrogen. After 30 min. of the carbon dioxide hydrogenation reaction, the peak intensity assigned to Rh-Rh scattering inc reased corresponding to the increase in the catalytic activity.