Cobalt and cobalt carbide on alumina/NiAl(110) as model catalysts. Issue 24 (8th November 2017)

• Record Type: Journal Article
• Authors: Zhang, Tianfu; Wu, Jingsong; Xu, Yuqun; Wang, Xiaoping; Ni, Jun; Li, Yongwang; Niemantsverdriet, J. W. (Hans)
• Is Part Of: Catalysis science & technology. Volume 7:Issue 24(2017)
• Page Start: 5893
• Page End: 5899
• Publication Date: 2017-11-08
• Subjects: Catalysis -- Periodicals; 541.395
• DOI: 10.1039/c7cy01806a
• Languages: English
• ISSNs: 2044-4753

Abstract

Abstract : Homogeneously dispersed Co nanoparticles on alumina/NiAl(110) exhibit good thermal stability and serve as suitable model catalysts for Fischer–Tropsch synthesis. Abstract : Cobalt is an important catalyst for Fischer–Tropsch synthesis, and it can form cobalt carbide under syngas (CO + H2 ) reaction conditions, especially in CO-rich mixtures. As cobalt carbide has been credited as a promoter which brings about significant selectivity changes in CO hydrogenation, we are interested in studying it using a surface science approach, to understand its interaction with important reaction intermediates. In the present study, we use a NiAl(110) surface to produce a flat alumina film and prepare cobalt and cobalt carbide thereon. We find that cobalt is thermally stable up to 800 K on alumina/NiAl(110). Different preparation temperatures result in different morphologies of the surface. Cobalt carbide is obtained by evaporating cobalt in an C2 H4 environment, as proved by the appearance of a C 1s peak at 283.3 eV of carbidic carbon and at 286.2 eV of chemisorbed CO on cobalt carbide in the XPS spectra. Large cobalt carbide crystals with a typical size of 100 nm × 50 nm are revealed by STM. The results show that cobalt and cobalt carbide on alumina/NiAl(110) can serve as suitable model systems for studying structures, adsorption and catalytic properties.