Facile and template-free fabrication of mesoporous 3D nanosphere-like MnxCo3−xO4 as highly effective catalysts for low temperature SCR of NOx with NH3. Issue 7 (5th January 2018)

• Record Type: Journal Article
• Authors: Hu, Xiaonan; Huang, Lei; Zhang, Jianping; Li, Hongrui; Zha, Kaiwen; Shi, Liyi; Zhang, Dengsong
• Is Part Of: Journal of materials chemistry. Volume 6:Issue 7(2018)
• Page Start: 2952
• Page End: 2963
• Publication Date: 2018-01-05
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c7ta08000j
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : Mesoporous 3D nanosphere-like Mn x Co3− x O4 was obtained via a template-free method. The formation mechanism was proposed and the synthesis conditions were carefully investigated. The operating temperature window was 75–325 °C when the NO x conversion was above 80%. Abstract : Mesoporous 3D Mn x Co3− x O4 nanospheres with an open structure were fabricated through a template-free and facile approach. The Mn x Co3− x O4 achieved a specific surface area as high as 143.7 m 2 g −1 . The process was systematically studied via TEM, HRTEM, EDS, ICP, XRD, TG, pH and FTIR. A two-step formation mechanism, namely the formation of CoOOH and MnO2 by a redox reaction between KMnO4 and Co(NO3 )2 ·6H2 O, followed by a calcination process in air, was proposed. The synthesis conditions including the reaction duration, reaction temperature, reactant concentration, feeding ratio, calcination temperature and the types of cobalt precursor used were also carefully investigated. This indicates that the approach is universal, green, facile, controllable and effective. The Mn x Co3− x O4 catalysts exhibited outstanding performance in the application of low-temperature selective catalytic reduction of NO x with NH3 . A wide working temperature window of 75 to 325 °C (NO x conversion above 80%) was achieved. The good performance benefited from the high BET surface area, a strong adsorption capacity, abundant acid sites, robust redox properties, abundant oxygen vacancies and metal–metal interactions in Mn x Co3− x O4 .