Regulation of metal-support interaction for enhanced Fischer-Tropsch synthesis over Co/TiO2 catalysts

The Fischer-Tropsch synthesis (FTS) performance of Co/TiO 2 supported catalysts is strongly influenced by the TiO 2 crystal phase. It was found that Co/r-TiO 2 (rutile) exhibited high FTS activity, while Co/a-TiO 2 (anatase) showed negligible activity due to facile reduction of a-TiO 2 , which induced TiO x migration over Co nanoparticles under H 2 to form a strong metal-support interaction (SMSI) layer. The formed TiO x layer would encapsulate Co active sites and suppress CO chemisorption with low activity. However, when a-TiO 2 support was pre-reduced in H 2 before Co loading, the resulting Co/a-TiO 2 (H 2 ) catalyst achieved a remarkable increase for CO conversion from 0% to 60.7%. Structural characterization confirmed that H 2 pretreatment generated abundant oxygen vacancies in a-TiO 2 (H 2 ), which effectively regulated the interaction between Co and TiO 2 support. As a result, the SMSI-induced encapsulation was inhibited with more exposed metallic Co active sites, which would enhance CO chemisorption and catalytic activity. This work presents an effective H 2 pretreatment strategy for tailoring SMSI-governed interfacial structure and optimizing the FTS performance of Co/TiO 2 catalysts.