Fe₃O₄ Nanoparticles Supported on Modified Coal toward Catalytic Hydrogenation of Coal to Oil

Iron-supported catalysts exhibit good catalytic performance in direct coal liquefaction (DCL), but the effect of the carrier on the performance of the composite catalyst is unclear. In this paper, a simple solid-state synthesis strategy for the preparation of coal-loaded Fe₃O₄ nanoparticles (Fe₃O₄/Coal) and the hydrochloric acid treatment of coal-loaded Fe₃O₄ nanoparticles (Fe₃O₄/Coal-HCl) is presented. The resulting composite was used as a catalyst for DCL. The effects of supports on the structure and performance of iron-supported catalysts have been illustrated. After the acid pretreatment of the catalyst carrier coal, the surface structure and functional groups changed, which affected the aggregation morphology of the Fe₃O₄ active component. The Fe₃O₄/Coal-HCl catalyst improved the catalytic performance of DCL with conversion and oil yield of 98.02 and 49.96 wt %, respectively. The result shows that pretreatment can be an effective way to modify the surface of the catalyst carrier coals, thereby further improving the catalytic performance of composites. The iron-based composites prepared by the solid-state route show great potential as supported catalysts in DCL.