Effect of calcination temperature on structural properties and catalytic soot combustion activity of MnOx/wire-mesh monoliths
| Autor: | Geng Liu, Jie Meng, Jiahuan Yu, Li Chen, Hui Wan, Peng Zhao, Guofeng Guan, Lei Wang, Fan Fang, Nengjie Feng |
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| Rok vydání: | 2019 |
| Předmět: |
Materials science
General Physics and Astronomy chemistry.chemical_element 02 engineering and technology Manganese engineering.material 010402 general chemistry 01 natural sciences Hydrothermal circulation law.invention Catalysis Coating X-ray photoelectron spectroscopy law Calcination Surfaces and Interfaces General Chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics Exfoliation joint 0104 chemical sciences Surfaces Coatings and Films chemistry Chemical engineering engineering Nanorod 0210 nano-technology |
| Zdroj: | Applied Surface Science. :1088-1103 |
| ISSN: | 0169-4332 |
| DOI: | 10.1016/j.apsusc.2018.10.223 |
| Popis: | Manganese Oxides (MnOx) growing on AISI304 stainless steel wire-mesh monoliths with excellent catalytic performance and firm adhesion were synthesized via a hydrothermal route. The effect of calcination temperatures was deeply investigated. Systematic characterizations including XRD, Raman spectra, FT-IR, N2 adsorption-desorption, SEM, HRSTEM-EDS, XPS, H2-TPR, CO-TPR, O2-TPD, Soot-TPR and ultrasound tests were conducted. With temperature increasing from 500 to 800 °C, the coating phase changes from α-MnO2 nanorods to MnCrO3 nanoblocks. Besides, MnCrO3 can tightly bond MnO2 with substrate as an interphase, and it also remarkably accelerates soot oxidation. The specimen calcined at 550 °C (MSS550) shows hierarchical pore structure with abundant accessible sites and more potassium content than MSS500 and MSS600. MSS700 presents the most surface oxygen species, high-valence metal elements and bulk potassium, thus showing the best activity. K+ would effectively activate gas O2 forming O2−, O22− and improve the redox properties while Cr6+ and Fe3+ dopants would generate numerous oxygen vacancies and intensify stability. Moreover, MSS700 displays good stability and catalytic activity under repeatability test and ultrasonic treatment. The exfoliation rates of all the samples are only 0.08 ± 0.03 wt%. This series of catalysts may satisfy the harsh conditions of active regeneration and show excellent performance for passive regeneration. |
| Databáze: | OpenAIRE |
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