Catalysis of xylose to furfural by metal salts in a methanol–water system

Abstract Furfural (FF), an important biomass platform compound, is extensively utilized in the synthesis of high‐value‐added chemicals, fuels, resins, and pharmaceuticals. To achieve the efficient conversion of xylose into FF, we systematically screened a series of metal salt catalysts in a homogeneous methanol–water system and thoroughly investigated their catalytic performance and reaction mechanisms. The results demonstrated that AlCl 3 exhibited the optimal catalytic activity in this reaction, achieving >99% xylose conversion and a 77.3% FF yield under the conditions of 160 °C and 2 h of reaction. Kinetic studies indicated that the conversion of xylose to intermediates was the rate‐determining step, with an apparent activation energy of 42.97 kJ mol −1 . Mechanistic analysis further revealed that AlCl 3 possesses both Lewis and Brønsted acid sites, which synergistically catalyze the multi‐step reactions – including isomerization, ring‐opening, dehydration, and cyclization – of xylose to form FF. This study develops a green and efficient catalytic system prototype with low cost, which not only clarifies the structure–performance relationship of AlCl 3 and the dual function of the methanol–water system, but also provides a theoretical foundation and technical basis for the sustainable production of biomass‐based FF.