Study on performance of Fe2N catalyst modified by hydrophobic PDVB-DMF for Fischer-Tropsch synthesis

Abstract

Fe-based catalysts are commonly used in Fischer-Tropsch synthesis. However, high water pressure in the process can easily lead to oxidation and deactivation of the active phase of the catalyst. Therefore, timely removal of the generated water from the catalyst surface is a key measure to prevent oxidation of the active phase and prolong the lifetime of the catalyst. In this work, hydrophobic agent-porous polydivinylbenzene was mixed with Fe₂N catalyst. The hydrophobicity of porous polydivinylbenzene accelerated the water migration in local microenvironment. This strategy effectively balanced the adsorption and release of water on the catalyst surface, reduced the occupation of water on the active site and promoted the efficient conversion of syngas. The CO conversion of Fe2N without porous hydrophobic agent was only 34.8%. The active phase was oxidized during the reaction. While CO conversion of Fe2N mixed with porous hydrophobic agent was as high as 80.2%, and no oxidation of active phase was observed after reaction. This work shows that hydrophobic polymers have excellent effects in optimizing catalyst microenvironment, improving reaction efficiency and product selectivity, and thus provides a new strategy for syngas conversion.