Iron oxychloride-based heterogeneous Fenton pretreatment of corn stover for enhanced sugars production

Homogeneous Fenton reaction using Fe2+/H2O2 represents a green conventional alternative for lignocellulose pretreatment, but some disadvantages such as time-consuming, acidic pH, and forming iron-based sludge limit its application. Here we present an Iron Oxychloride (FeOCl)-based heterogeneous Fenton method to pretreat corn stover (CS, an abundant agriculture waste), which can be a promising approach to overcome the limitation of Fe2+/H2O2-based homogeneous Fenton pretreatment (FP). The reducing sugars yield of CS treated by this approach for 6 h was about 3 times higher than that of untreated CS and also that of CS treated by FP for 72 h. Compared with the need of low pH by FP, the pH required for FeOCl-based heterogeneous Fenton pretreatment (HFP) can be extended to the range of neutral yet maintaining similar pretreatment output. In addition, the FeOCl catalyst can be easily recovered, and its catalytic activity remains 90% even after repeated use for five times, thus reducing the production of iron-based sludge as a by-product in the pretreatment process. Our results shed light on developing a mild, clean, and low-cost pretreatment strategy for efficient lignocellulose biorefinery.