LAUSR

The development of improved catalysts requires insights into the relationship between catalytic activity and catalyst structure, including the underlying reaction mechanism. Here, we demonstrate a unique set of catalyst extrudate sensors that allow for the simultaneous detection of local temperature by luminescence thermometry, and of surface species by shell-isolated nanoparticle-enhanced Raman spectroscopy. This sensing approach was applied to the characterization of direct conversion of syngas into hydrocarbons and C2+ oxygenates over supported Rh and RhFe catalysts. Luminescence thermometry demonstrated a mismatch between the set temperature and the local catalyst temperature, with variations up to 40 °C. Furthermore, by investigating the surface species on varying extrudate and catalyst compositions, we identified tilted carbonyl species on the Rh/SiO2 interface that are probable precursors for the hydrogen-assisted CO dissociation. The implementation of extrudate catalyst sensors as a characterization tool provides a unique approach towards the further understanding of the relevant parameters in catalysis.Multi-modal approaches to simultaneously characterize different aspects of a reaction in situ are not readily accessible. Here, catalyst extrudates equipped with both luminescence thermometry and Raman spectroscopy sensors are introduced, providing an in-depth picture for the conversion of syngas on a supported rhodium catalyst.