Oxygen vacancies enriched Ir/WOx catalysts for the directly chem-catalytic conversion of cellulose to ethanol

Tungsten and its oxides are highly versatile catalysts with unique properties that hold great promise for a wide array of applications, including biological pathways and chemical processes. The chemo-catalysis of cellulose to ethanol presents a promising avenue for ethanol synthesis with the potential for enhanced efficiency compared to conventional methods, offering a sustainable and carbon–neutral alternative to existing petrochemical and biological processes. Herein, Ir/WO x catalysts enriched with oxygen vacancies were meticulously prepared and demonstrated remarkable catalytic performance in converting cellulose to ethanol directly in the presence of tungstic acid. The catalyst achieved a high ethanol yield of 66.5% under optimal reaction conditions, approaching the theoretical yield limit of traditional ethanol fermentation. Characterization results revealed the presence of oxygen defects, Bronsted/Lewis acidity, and Ir nanoclusters on the catalyst surface, working synergistically to facilitate the cascade catalysis of cellulose hydrolysis, sugar retro-aldol condensation reaction, and C2 intermediate hydrodeoxygenation to ethanol. In situ Fourier transform infrared spectrometer analysis confirmed the catalyst's ability to enhance the adsorption and activation of ethylene glycol for ethanol production. By manipulating subtle structural features, this study offers a fresh perspective on tungsten group catalyst design and underscores the importance of synergistic effects among catalytic sites for the efficient production of ethanol from cellulose.