EELS Study of Co-Based Fischer-Tropsch Catalysts on TiO₂ and SiO₂ Supports

Abstract

As a potential way to ease the energy crises, Co-based Fischer-Tropsch (FT) heterogeneous catalysts have been extensively studied. Mn is found to be an effective promoter which could increase the selectivity of the catalysts. The enhanced catalytic performance is due to the generation of Co-Mn mixed oxide species that could potentially create active sites of more selectivity. That means the location of the Mn-promoter on the catalyst surface is a very important factor for the FT catalysis studying. TiO 2 and SiO 2 are two commonly used supports. For TiO 2 support, strong metal support interaction (SMSI) has been reported. On the contrary, SiO 2 is considered an inert support without any SMSI. In this presentation, by using the Z-contrast imaging and EELS, we will show the Mn distribution and migration in Co/TiO 2 and Co/SiO 2 catalysts. The different morphologies of the two catalysts will demonstrate that the Oxygen vacancies are the key factors controlling the Mn promotion effect in FT catalysis. [1,2]