Direct Methanol Synthesis from Cellulose Using a Tungsten-Promoted Cu-Based Multifunctional Catalyst

Methanol is not only an essential building block for modern chemical industries but also a promising and feasible alternative marine fuel. Conventional methanol production involves high-temperature reforming/gasification of natural gas, coal, and biomass, followed by high-pressure catalytic synthesis, resulting in substantial energy consumption. To address this issue, a novel multifunctional WO_x–Cu/TiO₂–Al₂O₃ (W–Cu–TiAl) catalyst was developed in this work that allows cellulose to be directly converted into methanol in a one-pot process. It was demonstrated that the loading of tungsten greatly improved the catalytic activity of the copper-based catalysts, allowing the cellulose to yield 51.6% methanol by reacting at 250 °C for 10 h. The catalysts were further characterized by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HR-TEM), Brunauer–Emmett–Teller analysis (BET), X-ray photoelectron spectroscopy (XPS), and temperature-programmed desorption of ammonia (NH₃-TPD) to reveal the possible catalyst structure–reactivity relationship. It was found that the introduction of tungsten not only reduced the total acid concentration of the catalyst but also slightly increased the binding energies of Cu 2p_3/2 and Cu 2p_1/2, which may be related to the increase in methanol yield. This work provides a new approach to cleaner production of methanol.