These are preliminary reports that have not been peer-reviewed. They should not be regarded as conclusive, guide clinical practice/health-related behavior, or be reported in news media as established information. For more information, please see our FAQs.
Ceria PNA TWC NO OX.pdf (818.09 kB)
Identification of Ru/Ceria Among Single Atom Ceria Catalysts as a Stable and Superior Material for Abatement of Diesel and Gasoline Engine Pollutants
Preprints are manuscripts made publicly available before they have been submitted for formal peer review and publication. They might contain new research findings or data. Preprints can be a draft or final version of an author's research but must not have been accepted for publication at the time of submission.
Atomically dispersed transition metals (Ru, Pd and
Pt) have been prepared on CeO2 and evaluated for NOx/CO abatement
applications for diesel and gasoline engines, such as low temperature passive
NOx adsorption (PNA), NO and CO oxidation, and three-way-catalysis (TWC). 0.5
wt% Ru/CeO2 catalyst (Ru is ~27 and ~7 times cheaper than Rh and Pd)
shows remarkable PNA performance, better than 1 wt% Pd/Zeolite: it achieves 100%
removal of NOx during vehicle cold start. FTIR measurements reveal the
formation of stable Ru(NO) complexes as well spill-over of NO to CeO2
surface via the Ru-O-Ce shuttle, explaining high NO storage. Notably, Ru/ceria
survives hydrothermal aging at 750 ⁰C without loss of PNA
capacity. It is also a robust NO oxidation catalyst, considerably more active
than Pt or Pd/CeO2. Expanding the repertoire of Ru/CeO2
catalytic applications, we further find 0.1 and 0.5 wt% Ru/CeO2 to
be excellent TWC catalysts, rivaling best single-atom Rh supported materials. Our
study pushes the frontier of precious metal atom economy for environmental
catalysis from uber expensive Rh/Pd/Pt to more sustainable cheaper Ru and
highlights the utility of single-atom catalysts for industrially relevant
The research at PNNL was supported by the U.S. Department of Energy, Energy Efficiency and Renewable Energy, Vehicle Technology Office. Experiments were conducted in the Environmental Molecular Sciences Laboratory (EMSL), a national scientific user facility sponsored by the Department of Energy’s Office of Biological and Environmental Research at Pacific Northwest National Laboratory (PNNL). PNNL is a multi-program national laboratory operated for the DOE by Battelle Memorial Institute under Contract DE-AC06-76RL01830. We acknowledge the support of CLEERS (Crosscut Lean Exhaust Emissions Reduction Simulations). CLEERS is an initiative funded by the U.S. Department of Energy (DOE) Vehicle Technologies Office to support the development of accurate tools for use in the design, calibration, and control of next generation engine/emissions control systems that maximize efficiency while complying with emissions regulations.