Tungsten carbides are possible low-cost replacements for noble metal catalysts, but the role of different carbide stoichiometries (W₂C, WC) and their polymorphs for catalytic behavior is poorly understood. We develop a “dynamic, isothermal” carburization of WO₃ in a mixture of CH₄ and H₂ to control phase composition and catalytic properties. A design-of-experiments approach reveals that the key parameters are synthesis temperature (670 to 775 °C) and addition of silica as stabilizer (0 or 70 mol%). X-ray diffraction shows that the composition can be adjusted from 14 to 99 wt% W₂C, complemented by WC and a small fraction of W metal. Crystalline domain sizes for W₂C are smaller than those of WC (≥10 nm), affording thermodynamic stabilization of W₂C in agreement with computational predictions (Shrestha et al., Chem. Mater. 2021, 33, 4606–4620). The amount of CO adsorbed scales with W₂C content, and so does the performance in butyraldehyde or toluene hydrogenation.

碳化钨可能是贵金属催化剂的低成本替代品，但对不同碳化物化学计量（W ₂ C、WC）及其多晶型物对催化行为的作用知之甚少。我们开发了 WO ₃在 CH ₄和 H ₂混合物中的“动态、等温”渗碳，以控制相组成和催化性能。实验设计方法表明，关键参数是合成温度（670 至 775 °C）和添加二氧化硅作为稳定剂（0 或 70 mol%）。X 射线衍射表明，该组成可以从 14 到 99 重量％的 W ₂ C进行调整，并辅以 WC 和少量 W 金属。W _{2 的}晶畴尺寸C 小于 WC (≥10 nm)，提供 W ₂ C 的热力学稳定性，与计算预测一致（Shrestha 等人，Chem. Mater. 2021, 33, 4606–4620）。CO吸附量与W ₂ C含量成比例，丁醛或甲苯加氢性能也如此。