Environmental TEM Studies of CoMn nanoalloys as Model Fischer-Tropsch Catalysts

Fischer-Tropsch(FT) reaction involves the hydrogenation of carbon monoxide to hydrocarbons typically by group VIII metals [1]. Cobalt is one of the first metals used as FT catalyst and is typically mixed with Mn to promote carbon monoxide conversion to more valuable higher (C5+) hydrocarbons and olefins. The properties of metal catalysts can be controlled by fine-tuning chemical composition, surface oxidation, structure and dimension[2,3]. However, the performance of FT catalysts is strongly affected by oxidizing and reducing pre-treatments[1]. In this case, well-defined size and compositions of CoMn nanoalloys were synthesized and studied in oxidizing and reducing conditions as necessary for its viability as FT catalyst. Here in situ TEM was performed to determine the elemental distributions and morphological changes in the CoMn nanoalloys upon exposure to oxidizing and reducing environments to elucidate the observed nanoalloys’ catalytic properties.