Insight into high-performance of La–Ce–MnOx oxides with different calcination temperatures for diesel soot combustion

ABSTRACT

A series of La–Ce–MnOx catalysts derived from the precipitation of acetate salt and ammonium carbonate were calcined at different temperatures and applied for the catalytic oxidation of soot from diesel exhausts. The structure states of the as-prepared catalysts and catalytic behaviour for soot oxidation were studied by many characterization techniques such as XRD, XANES, N₂ adsorption–desorption, TPR, O₂-TPD, XPS and TGA. XANES results display most Mn species are Mn⁴⁺ when the samples are calcined at 500 and 600°C. However, for MCLa-700 and MCLa-800 catalysts, the predominance valence is 3+ ions. The MCLa-500 and MCLa-600 catalysts possess higher concentrations of surface active oxygen evidenced by H₂-TPR and soot-TPR. Therefore, the combustion rate of soot over MCLa-600 catalyst is remarkably increased with the T₁₀, T₅₀ and T₉₀ at 318°C, 360°C and 388°C under NOx atmosphere respectively.

GRAPHICAL ABSTRACT

KEYWORDS:

• Soot combustion
• oxygen species
• manganese species
• calcination temperature
• high activity

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability

The data used to support the findings of this study are available from the corresponding author upon request.

Additional information

Funding

This work was supported by National Natural Science Foundation of China: [Grant Number 21706150]; Natural Science Foundation of Shaanxi Province: [Grant Number 2019JQ-789]; Xiangnan Key Laboratory of Rare and Precious Metal Complexes and Their Applications [Grant Number 2019XGJSKFJJ04].