Ultra-large-scale Synthesis of Fe₃O₄ Nanoparticles and Their Application for Direct Coal Liquefaction

Ultra-large-scale synthesis of iron oxide nanoparticles (875 g) has been achieved in a single reaction via a facile solution-based dehydration process. The obtained nanoparticles capped with hydrophobic oleic acid ligands are magnetite with the average size of 5 nm. The synthesized samples exhibit a higher catalytic activity toward the direct coal liquefaction (DCL) than the commercial Fe₃O₄ powders. The conversion, oil yield, and liquefaction degree with the synthesized Fe₃O₄ nanoparticles are 89.6, 65.1, and 77.3%, respectively. The excellent catalytic performance of the synthesized Fe₃O₄ nanoparticles can be attributed to their extremely small size and high dispersity. This facile approach to prepare highly active nanocatalyst for the DCL will be applicable for future industrial processes