Correlation of metal-organic framework structures and catalytic performance in Fischer-Tropsch synthesis process

摘要

Two typical metal-organic frameworks (MOFs), i.e. tris(pyridine-2-carboxylato)-cobalt(III) monohydrate (MOF-1) and (mu(2)-pyridine 2,6-dicarboxylato)(pyridine 2,6-dicarboxylato) pentaaqua dicobalt(II)dihydrate (MOF-2) were employed for preparation of cobalt Fischer-Tropsch catalysts. Both MOF-derived catalysts were obtained by direct pyrolysis in N-2 atmosphere at 500 degrees C. The pyrolysis of desired MOFs resulted nanoparticles embedded in the porous carbon matrix. Such catalysts can serve as useful catalysts for FT synthesis. Co-MOF-1 derived catalyst exhibited carbon monoxide conversion of 74.8% and selectivity towards long-chain hydrocarbons (C-5(+)) of 49.2%. Also, it showed selectivity for short-chain hydrocarbons (C-2-C-4) of 36.19% for 50 h on steam while Co-MOF-2 derived catalyst displayed CO conversion of 81.6% and selectivity for long-chain hydrocarbons (C-5(+)) and short-chain hydrocarbons of 56.8% and 28.2%. The superb activity and catalytic efficiency can be ascribed to the MOF precursors structures. This study investigated the relationship between MOF structure and catalytic performance and presented a new approach to design novel super active catalysts with preferable selectivity for Fischer-Tropsch synthesis by opting the suitable MOF precursors.