Tom van Deelen

PhD Candidate

Employed since: November 2014
Phone: +31 6 2273 6385
Room: 4th floor study area

Supported cobalt nanoparticles to elucidate structure-performance relationships in the Fischer-Tropsch synthesis

Sponsor: Shell Global Solutions
Promotor: Prof. dr. ir. Krijn de Jong

In the Fischer-Tropsch synthesis (FTS), synthesis gas (CO and H2) is converted into hydrocarbon products over transition metal catalysts. The FTS is a highly relevant research topic in light of the depleting fossil fuel reserves and the demand for ultraclean transportation fuels and has therefore attracted considerable attention of the scientific community over the past decades. Supported cobalt catalysts are typically applied for long-chain hydrocarbon synthesis in FTS [1]. 

Much research has been devoted to understanding the effect of the structure of  cobalt nanoparticles (NPs) on its catalytic performance. For example, a maximum in activity of cobalt NPs exists at a certain particle size (~6 nm) despite increasing specific cobalt surface area for smaller particles. This observation is known as the cobalt particle size effect [2]. However, the influence of the initial shape of the NPs, which is related to the exposed crystal planes and the number of edge and corner sites, is largely unknown. Proper control of the NPs size and shape is required to thoroughly investigate such structural aspects.

In this project, we have started off by using colloidal synthesis techniques to obtain cobalt NPs of uniform size and specific shapes. These well-defined NPs will subsequently be deposited on suitable support materials. Extensive characterization of the supported NPs will be combined with catalytic testing in FTS to assess the catalytic performance (activity, selectivity and stability). Via this approach, it is anticipated that more insight into structure-performance relationships will be gained.

Figure 1: example of the narrow Co particle size distributions obtained via colloidal synthesis [3].

[1] A.Y. Khodakov et al., Chem. Rev. 107, 1692-1744 (2007)
[2] G.L. Bezemer et al. J. Am. Chem. Soc. 128, 3956-3964 (2006)
[3] V. Iablokov et al., Nano Lett. 12, 3091-3096 (2012)