Fischer-Tropsch Synthesis over Supported Pt-Mo Catalyst: Toward Bimetallic Catalyst Optimization

The product distribution of the Fischer-Tropsch (FT) process demonstrates a strong dependence upon the choice of catalyst, catalytic support, and reaction temperature. To develop understanding of the factors that underpin catalytic activity, we performed density-functional-theory (DFT)-based first-principles calculations for syngas reaction over bimetallic (Pt-Mo) catalysts including bimetallic surfaces and alloyed nanoparticles (NPs) positioned on a top of gamma-Al2O3 substrate. It was found that catalytic activity of the (Pt-Mo) nanoparticles depends upon (i) the selectivity and reactivity of different atomic sites at the surface that may significantly affect the kinetics of different stages of the FT synthesis and (ii) the optimal composition of the NP allowing increasing the methane production at the first stage of the FT synthesis. This work highlights the main mechanisms that govern bimetallic catalyst activity for the FT synthesis. Similar considerations could be developed for any bimetallic catalytic system and any catalytic reactions. The results presented here should help to provide a solid basis for the rational design and/or improvement of many bimetallic catalysts.