Crystal defects Boost cellulose conversion to C2 alcohols over Pd/WO3 catalysts

A large number of crystal defects were found on the Pd/o-WO3 surface, which improved the efficiency of cellulose conversion to C2 alcohols. [Display omitted] •The optimized Pd/o-WO3 catalyst, rich in crystal defects, yielded an impressive 80.9% of C2 alcohols.•The small W/O occupancy rates and long W-O bond length resulted in a large number of crystal defects over Pd/o-WO3.•Crystal defects facilitated the formation of W5+–OH and Pd-O(H)-W interactions, which further synergistically enhance hydrogenation capacity and acidity.•Cellulose conversion pathways included hydrolysis, retro-aldol condensation, and hydrogenation. Converting cellulose into C2 alcohols presents a sustainable alternative to fossil fuels, contributing to the development of eco-friendly and economically viable biofuels and chemicals. Tungsten oxide (WO3) is a key solid acid catalyst for this process, yet limited research explores its diverse morphologies and unique catalytic effects. This study investigates diverse WO3 morphologies (nanosheets, nanoflowers, nanoblocks, and tetrahedral octahedra) in combination with Pd for converting cellulose to C2 alcohols. Optimized conditions with Pd/o-WO3 catalyst resulted in the highest C2 alcohols (ethylene glycol and ethanol, 80.9 %), notably yielding 64.8 % ethylene glycol. Extensive characterizations and DFT calculations reveal the smaller element occupancy rates and a longer W-O bond length led to a large number of crystal defects over Pd/o-WO3. It facilitated the formation of W5+–OH sites and Pd-O(H)-W interactions, further synergistically enhancing hydrogenation ability and acidity. Designed experiments to elucidate cellulose conversion pathways, including hydrolysis, retro-aldol condensation, and hydrogenation. This study emphasizes the unique impact of WO3 morphologies and underscores the importance of supporting crystal defects for catalytic performance in eco-friendly biofuel and chemical production.