Synthesis of different structured FePO4 for the enhanced conversion of methyl cellulose to 5-hydroxymethylfurfural

FePO4 catalysts with branch-like, flower-like, and spherical morphologies were synthesized for the conversion of methyl cellulose to 5-hydroxymethylfurfural (5-HMF) via a hydrothermal route. The molar ratio of Fe3+ and H2PO4- ions in the reaction system played a crucial role in the morphology of FePO4. Compared with flower-like, spherical and amorphous FePO4, branch-like FePO4 presented a better catalytic performance in the cellulose conversion and 5-HMF yield. The branch-like FePO4 retained a branch structure after recycling five times in the bi-phasic reaction process. The insolubility of low temperature and partial dissolution of elevated temperature were responsible for the excellent catalytic activity of the FePO4 phase-change catalyst. The combined effect of H+ ions and iron species generated from the hydrolysis of FePO4 can be favorable for the enhanced yield of 5-HMF.