Operando evaluation of dynamic structural modifications on Rh nanoparticle surfaces throughout catalytic discount of NO utilizing an environmental high-voltage electron microscope–quadrupole mass spectrometer

Standard characterization methods reminiscent of transmission electron microscopy (TEM) can not visualize the delicate structural modifications in Rh nanoparticles through the discount of NO to N₂ on their floor. Therefore, on this research, we used an environmental response science high-voltage electron microscope outfitted with a quadrupole mass spectrometer (QMS) system to conduct operando atomic-scale evaluation of the NO discount course of on Rh nanoparticles supported on ZrO₂. This revolutionary setup enabled us to watch dynamic floor structural modifications whereas concurrently monitoring the manufacturing of N₂ and consumption of NO underneath related response circumstances. Excessive-resolution TEM observations and kinetic calculations primarily based on QMS information confirmed the presence of a pseudocyclic transitional state between Rh metallic and RhO₂ inside an unstable oxide monolayer on the floor of the Rh nanoparticles, which is a hitherto undocumented phenomenon. A comparability of experimental information with the corresponding simulated photographs revealed believable catalytic mechanisms for the discount of NO to N₂ at three completely different temperature ranges (200–500, 500–600, and 600–700 °C). At low temperatures, the response primarily happens on a skinny RhO₂ movie shaped on the nanoparticle floor, which defies the longstanding consensus that the discount of NO happens on Rh metallic websites. Our methodology enabled the direct remark of transient floor states and revealed their skill to dictate the general response dynamics. The findings of this research present insights into floor catalytic reactions on nanoparticles underneath sensible circumstances in addition to can information future research on catalytic mechanisms.