CO oxidation activity of Pt/CeO2 catalysts below 0°C: platinum loading effects
A collaboration of Prof Konstantin Neyman and Dr Albert Bruix with researchers from the Boreskov Institute of Catalysis of the Russian Academy of Sciences in Novosibirsk (Russia) led by Prof Andrei Boronin opens the way for reducing emissions of automotive pollutants. In a recent study, scientists suggested new principles of design and synthesized catalysts able to transform toxic molecules in air at temperatures below 0ᵒC. This is essential to remove the harmful cold-start emissions generated by vehicles during the first few minutes after ignition when the catalytic converters are not warm enough to work properly.
CO oxidation activity of Pt/CeO2 catalysts below 0 °C: platinum loading effects, Andrei Boronin, Elena Slavinskaya, Alberto Figueroba, Albert Bruix, Konstantin Neyman and co-workers, Applied Catalysis B: Environmental 286 (2021) 119931, [doi.org/10.1016/j.apcatb.2021.119931]
Reducing the operating temperature of oxidation catalysts is important for designing energy-efficient processes, extending catalyst lifetime, and abating pollutants, especially in cold climates. Herein, high CO oxidation activity at sub-ambient temperatures is reported for Pt/CeO2 catalysts with a high content of Pt in the form of dispersed Pt2+ and Pt4+ centres. Whereas the reference 1 wt%Pt catalyst was active for CO oxidation only above 100ᵒC, the 8 and 20 wt%Pt catalysts converted 60 and 90 % of CO, respectively, below 0ᵒC. Ionic platinum was shown to facilitate oxygen release from ceria and lower the light-off temperature of the reaction occurring through the Mars-van-Krevelen mechanism. However, the remarkable activity observed at sub-ambient temperatures for the ≥8 wt%Pt catalysts is proposed to involve O2 and CO reactants weakly adsorbed on PtOx clusters. The synergies between ionic platinum and nanostructured ceria reported in this work advance the knowledge-driven design of catalysts for low-temperature oxidation reactions.
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