In-situ impregnation of β-FeOOH on coal by solid-state reaction toward direct coal liquefaction

Herein, β-FeOOH nanoparticles supported on coal (β-FeOOH@C) were prepared by a solid-state in-situ impregnation and tested for the direct coal liquefaction (DCL) process. The β-FeOOH nanoparticles with ~10–50 nm were uniformly loaded over coal through a solid-state reaction among ferrous chloride, sodium hydroxide and coal. The obtained β-FeOOH@C solid showed enhanced catalytic performance for DCL compared with unsupported β-FeOOH nanoparticles. The conversion and oil yield achieved by β-FeOOH@C were 92.88 and 48.78% in the catalytic liquefaction of Dahuangshan lignite. The solid-state in-situ impregnation with coal as support shows great potential to prepare effective iron-based catalysts toward practical DCL.