Study on the preparation of Highly Active and Stable Cobalt on Carbon Nanotubes Catalysts for the Fischer-Tropsch reaction

Abstract

In the Fischer-Tropsch synthesis – the heterogeneously catalyzed conversion of syngas into hydrocarbon chains - transportation fuels can be produced from alternative sources to crude oil. In cobalt based Fischer-Tropsch catalysis the support material is generally oxidic in nature. A drawback of using oxidic supports is that they can form mixed compounds with cobalt that are not active in the FT catalysis and are only reducible at high temperatures. One way to overcome this problem is by the use of an inert support, e.g. carbon nanotubes (CNT). CNT exhibit a variety of interesting properties for support materials, including high mechanical strength, high thermal conductivity, and good chemical inertness in aggressive media. However, the well defined structures of the tubes would facilitate the study of the stability measures taken by means of surface roughening and heat treatment. The aim of this project was to prepare highly active cobalt on carbon nanotubes Fischer-Tropsch (FT) catalyst with low methane selectivity and a high C5+ selectivity, and to study the effects of surface roughening and heat treatment on the activity and stability of Co/CNT FT catalysts.

Research presented in this thesis has shown the potential cobalt supported on CNT have in Fischer-Tropsch catalysis. With a relatively simple preparation route, highly active Fischer-Tropsch catalysts were prepared.