Formation and catalytic properties of edge-bonded molybdenum sulfide catalysts on TiO2

The effect of preparation conditions (calcination atmosphere, sulfidation atmosphere, and sulfidation temperature) on the orientation Of MOS2 clusters on TiO2 supports was studied. Edge-bonded MoS2 clusters formed when the catalyst was sulfided in a flow of H2S/N-2 at 573 or 673 K. However, when sulfided in H2S/N-2 at higher temperatures than 773 K, the edge-bonded MOS2 clusters transformed to highly aggregated basal-bonded MOS2 clusters. Catalytic activity tests, using hydrogenation of 1-methylnaphthalene as a model test reaction, revealed that the turnover frequency on the catalyst with edge-bonded MOS2 clusters prepared by sulfiding at 573 K in H2S/N-2 was higher than that on the catalyst with basal-bonded MOS2 clusters prepared by sulfiding in H2S/H-2. (C) 2002 Elsevier Science (USA).