Bioethanol conversion from lignocellulosic biomass: a combined TiO 2 photocatalytic pretreatment and Pt/ W

Abstract Bioethanol production from lignocellulosic biomass is hindered by the need for efficient delignification and conversion processes. This laboratory‐scale study demonstrates a two‐step approach using Napier grass as feedstock. The steps were titanium dioxide (TiO 2 ) photocatalytic pretreatment followed by platinum/tungsten oxide (Pt/WO 3 )‐catalyzed chemocatalytic cascade conversion. Photocatalytic pretreatment with 2 wt% TiO 2 under UV irradiation for 2 h achieved a cellulose yield of 88.96 wt%, comparable with that of conventional alkaline pretreatment (88.41 wt%, 24 h) but requiring considerably less time. The subsequent cascade conversion using 3 wt% Pt/WO 3 catalyst produced bioethanol with a 47.7% yield at 230 °C within 10 h. The reaction proceeds through hydrolysis, retro‐aldol degradation, dehydration, and hydrogenation. Compared with conventional alkaline pretreatment, this method reduces pretreatment time from 24 to 2 h and eliminates the need for separate enzymatic hydrolysis and fermentation steps. The process shows strong potential for sustainable bioethanol production from agricultural waste biomass while reducing the use of hazardous chemicals.