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.