Developing a thermally stable Co/Ce-Sn catalyst via adding Sn for soot and CO oxidation

The thermal stability of the catalysts is of particular importance but still a big challenge for working under harsh conditions at high temperature. In this study, we report a strategy to improve the thermal stability of the ceria-based catalyst via introducing Sn. XRD, Rietveld refinement, and other characterizations results indicated that the formation of Sn-Co solid solution plays a key role in the thermal stability of the catalyst. The developed ternary 3%Co/Ce_0.5Sn_0.5O₂ catalyst not only exhibits outstanding thermal stability and resistance to SO₂ and H₂O for soot oxidation from diesel vehicle exhaust but also remains extraordinary thermal stability for CO oxidation. Remarkably, even after thermal aging at 1000°C, it still possessed high catalytic activity similar to that of the fresh catalyst.

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The developed 3%Co/Ce-Sn catalyst processes extraordinary thermal stability

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The Sn species could restrain the aggregation of Co active component

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The Sn-Co solid solution plays a key role in improving the thermal stability

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The 3%Co/Ce-Sn catalyst exhibited perfect and stable resistance to H₂O and SO₂

Surface oxygen species essential for the catalytic activity of Ce–M–Sn (M = Mn or Fe) in soot oxidation

Herein, transition metal (Mn and Fe)-doped Ce–Sn nanorod catalysts were successfully synthesized via a hydrothermal method.

Nickel and cobalt transfigured natural clay: a green catalyst for low-temperature catalytic soot oxidation

Modified 'natural clay' with Ni and Co nanoparticles explored as efficient catalyst for low-temperature soot oxidation activity studies.

Study on oxidation activity of Ce-Mn-K composite oxides on diesel soot

As an effective method, diesel particulate filter (DPF) technology has a great contribution in reducing soot emissions from diesel engines. To achieve passive regeneration of DPF at low temperatures, K-doped Ce_0.5Mn_0.5O₂ catalysts were synthesized using sol–gel method. The effect of K-doped catalysts-K_z–Ce_0.5Mn_0.5O₂-on the oxidation of soot had been studied by thermogravimetric analysis, and the corresponding catalytic properties were evaluated based on X-ray diffraction (XRD), hydrogen temperature programmed reduction (H₂-TPR), O₂ temperature programmed desorption (O₂-TPD) Raman spectroscopy (Raman), Brunauer–Emmett–Teller (BET) and Fourier-Transform-Infrared (FTIR).The results showed that K doping facilitated the oxidation of diesel particulate matter, which was indicated by the entire mass loss curve shifting to lower temperatures. K_0.2–Ce_0.5Mn_0.5O₂ showed the best performance among the series of K-doped catalysts. Compared with the findings for Ce_0.5Mn_0.5O₂, the ignition temperature of soot oxidation (T_i) had been lowered by 28 ℃, and the maximum peak combustion temperature (T_m) of the dry soot decreased by 61 °C. Furthermore, compared with the Ce_0.5Mn_0.5O₂-catalyzed reaction, K doping led to a lower activation energy and significantly improved pre-exponential factor. The minimum reaction activation energy of 27.46 kJ/mol was exhibited by K_0.2–Ce_0.5Mn_0.5O₂.

Gaseous and Particulate Emissions from a Chimneyless Biomass Cookstove Equipped with a Potassium Catalyst

Approximately three billion people cook with solid fuels, mostly wood, on open fires or rudimentary stoves. These traditional cooking methods produce particulate matter and carbon monoxide known to cause significant respiratory health problems, especially among women and children, who often have the highest exposure. In this work, an inexpensive potassium-based catalyst was incorporated in a chimneyless biomass cookstove to reduce harmful emissions through catalytic oxidation. Potassium titanate was identified as an effective and stable oxidation catalyst capable of oxidizing particulate matter and carbon monoxide. Using a cordierite monolith to incorporate potassium titanate within a bespoke, rocket-style, improved cookstove led to a 36% reduction in particulate matter emissions relative to a baseline stove with a blank monolith and a 26% reduction relative to a stove with no monolith. Additionally, the catalytic stove reduced particulate matter emissions by 82%, reduced carbon monoxide emissions by 70%, and improved efficiency by 100% compared to a carefully tended, three-stone fire. Potassium titanate was also shown to oxidize carbon monoxide at temperatures as low as 500 °C, or as low as 300 °C when doped with copper or cobalt.