Enhanced soot oxidation by oxygen vacancies via K ⁺ doped CuFe ₂ O ₄ spinel catalysts

Abstract

Summary Soot particulate emitting from diesel engines are serious to both human health and environment. Efficient catalyst is vital in diesel particulate filter technology to decrease soot oxidation temperature. Cu1−xKxFe2O4 (x = 0, 0.05, 0.1, and 0.15) catalysts are synthesized and analyzed with XRD, Raman, BET, SEM, TEM, TG, EDS, XPS, catalytic activity tests, and kinetic analysis. The results suggests that many factors affect the catalytic activity, and the contents of oxygen vacancies are dominant. A large amount of oxygen vacancies which facilitate to the soot oxidation are created with the assistance of K+, and they increase with the increasing doping contents. Excessive surface concentration of K+ may lead to the partially covering of active sites of the catalysts. Therefore, Cu0.9K0.1Fe2O4 catalyst exhibits the best catalytic activity in soot oxidation, which decreases the Tmax of soot by 279°C. This decrease makes it highly promising for application in diesel particulate filter.

Oxygen Vacancy-Dependent Photocatalytic Selective Synthesis of an Unsaturated Amide on Spinel CuFe2O4

“…The difference in the TGA curves between CFO-400 and untreated CuFe 2 O 4 materials at 600 °C corresponds to the weight ratio of oxygen vacancy. So the TGA results demonstrate that the amount of oxygen vacancies (number of oxygen vacancies/total number of oxygen) is 2.06% in CFO-400, which is consistent with the reported value of 2% in the literature for the CuFe 2 O 4 material. , So the chemical formula of CFO-400 is proposed as CuFe (2 III –2 x ) Fe 2 x II O 4– x (x=0.02). Density measurements were also undertaken for samples to check the presence of oxygen vacancies, which showed densities of 4.71 and 3.69 g/cm 3 for CFO and CFO-400, respectively.…”

“…So the TGA results demonstrate that the amount of oxygen vacancies (number of oxygen vacancies/total number of oxygen) is 2.06% in CFO-400, which is consistent with the reported value of 2% in the literature for the CuFe 2 O 4 material. 29,30 So the chemical formula of CFO-400 is proposed as CuFe (2…”

Recent Progress on Density Functional Theory Calculations for Catalytic Control of Air Pollution

“…Noble metals, known for their ability to reduce reaction temperatures, remain the preferred choice for enhancing catalytic performance. Additionally, there is growing interest in transition metal oxide catalysts due to their cost-effectiveness. − Researchers are actively exploring ways to achieve a high performance at reduced costs. These advancements hold great promise for cost-effective and efficient soot removal, ultimately contributing to improved air quality.…”