(6e) Thermally Stable and Highly Active Single Rh Atom Catalysts (Rh1/ceria) for NO Reduction
AIChE Annual Meeting
2022
2022 Annual Meeting
Catalysis and Reaction Engineering Division
In Honor of Norbert Kruse's Birthday (Invited Talks)
Sunday, November 13, 2022 - 4:50pm to 5:10pm
We found that atomically dispersed Rh cations on ceria, prepared via high-temperature atom trapping synthesis, are the active species for (CO+NO) reaction. This provides a direct link with the organometallic homogeneous Rh(I) complexes capable of catalyzing dry (CO+NO) reaction but without the stability concern. In particular, thermally stable Rh cations in 0.1wt% Rh1/CeO2 achieve full NO conversion at ~120 â°C with a TOF of ~ 330 hr-1 per Rh atom at 120 â°C. Under dry conditions, the main product above 100 â°C is N2 with N2O being the minor product. The presence of water promotes low-temperature activity of 0.1wt% Rh1/CeO2 starting at 50 â°C with full NO conversion at ~120 â°C. In the case with the wet stream, however, ammonia and nitrogen are the main products with only minor N2O amounts. We further show that ammonia formation correlates with the WGS activity of the material and thus, rhodium hydride Rh-H species are believed to be involved in this reaction.