Understanding the importance of N−doping for CNT-supported Ni catalysts for CO2 methanation. (15th August 2022)

• Record Type: Journal Article
• Authors: Gonçalves, Liliana P.L.; Meledina, Maria; Meledin, Alexander; Petrovykh, Dmitri Y.; Sousa, Juliana P.S.; Soares, O. Salomé G.P.; Kolen'ko, Yury V.; Pereira, M. Fernando R.
• Is Part Of: Carbon. Volume 195(2022)
• Page Start: 35
• Page End: 43
• Publication Date: 2022-08-15
• Subjects: Carbon nanotubes -- CO2 methanation -- N-doping -- HAADF-STEM; Carbon -- Periodicals; Carbone -- Périodiques; Koolstof; Toepassingen; Electronic journals; 546.681
• DOI: 10.1016/j.carbon.2022.03.059
• Languages: English
• ISSNs: 0008-6223

Abstract

Abstract: The N−doping of carbon nanotubes (CNTs) is widely accepted as an effective way to enhance the catalytic performance of CNT-supported Ni catalysts for CO2 methanation. To demonstrate, in a direct systematic comparison, the importance of N−doping for producing high-performance CO2 methanation catalysts, we developed two catalysts composed of 15 wt% Ni on pristine (Ni/CNT) and N−doped CNT (Ni/CNT−N) and correlated their catalytic performance with their properties. Compared to Ni/CNT, Ni/CNT−N achieved a higher X CO2 of 81.2% with S CH4 = 99.2% at a lower temperature of 400 °C, exhibiting excellent stability over 48 h time-on-stream testing. Our comprehensive comparative study demonstrated that the N−doped CNT support featured a better distribution of the Ni sites that were strongly interacting with the support, even with atomically dispersed Ni being observed by HAADF-STEM. This higher dispersion, enabled by the anchoring sites provided by the N−doping, is one of the main reasons for the enhanced performance of Ni/CNT−N, because it increases the H2 uptake capacity. Graphical abstract: Image 1