Simultaneous Fe₃O₄ Nanoparticle Formation and Catalyst-Driven Hydrothermal Cellulose Degradation

Breakdown and utilization of cellulose are critical for the bioenergy sector; however, current cellulose-to-energy conversion schemes often consume large quantities of unrecoverable chemicals, or are expensive, due to the need for enzymes or high temperatures. In this paper, we demonstrate a new method for converting cellulose into soluble compounds using a mixture of Fe²⁺ and Fe³⁺ as catalytic centers for the breakdown, yielding Fe₃O₄ nanoparticles during the hydrothermal process. Iron precursors transformed more than 61% of microcrystalline cellulose into solutes, with the composition of the solute changing with the initial Fe³⁺ concentration. The primary products of the breakdown of cellulose were a range of aldaric acids with different molecular weights. The nanoparticles have concentration-dependent tuneable sizes between 6.7 and 15.8 nm in diameter. The production of value-added nanomaterials at low temperatures improves upon the economics of traditional cellulose-to-energy conversion schemes with the precursor value increasing rather than deteriorating over time.