In situ generation of peracetic acid using phosphotungstic acid: A one-pot strategy for selective delignification of...

Peracetic acid (PAA) treatment is a promising delignification strategy for lignocellulose biorefinery; however, its cumbersome preparation has challenged industrial application. This work presents a facile approach for in situ PAA generation using phosphotungstic acid (PTA) as a catalyst in hydrogen peroxide-acetic acid (HPAC) system for one-pot global deconstruction and delignification of corn stover. With an HPAC concentration of 50% (v/v) and PTA loading of 1-1.5% (w/w), approximately 83.5% of lignin was removed. Meanwhile, 87.0-90.8% of glucan and 80.3-82.4% of xylan were retained. The streamlined process demonstrated exceptional enzymatic digestibility, reaching 92.9% and 82.4% glucose conversion under 5% and 15% solid loadings, respectively. Correlation analysis revealed that enzymatic hydrolysis efficiency primarily depended on the spatial structure of the pretreated substrate and its residual lignin content. This strategy successfully addresses the need for separate PAA synthesis through in situ generation and achieves efficient delignification in one step with remarkable carbohydrate retention. It provides an environmentally friendly and cost controllable pretreatment strategy, demonstrating significant potential for sustainable sugar production.