Zou Rui, Sun Kaihang, Shen Chenyang, Liu Chang-Jun
School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300350, China.
Collaborative Innovation Center of Chemical Science & Engineering, Tianjin University, Tianjin, 300072, China.
Phys Chem Chem Phys. 2022 Oct 27;24(41):25522-25529. doi: 10.1039/d2cp03842k.
Indium oxide is a promising catalyst for CO hydrogenation to methanol and has been extensively investigated in recent years. However, the studies on doped InO for methanol synthesis are relatively few, and tungsten-doped InO has not been reported yet. Herein, the mechanism of the methanol synthesis from CO hydrogenation on the defective W-doped InO model (W-InO_D) has been investigated density functional theory (DFT) calculations. The oxygen vacancy on the InO catalyst is essential for the activation and conversion of CO. The introduction of tungsten results in higher electron density and electron localization on the oxygen vacancy, thus facilitating the activation of CO. The methanol synthesis on the W-InO_D model takes the formate route the HCO intermediate. Compared with the InO_D model, the cleavage of the C-O bond, the removal of HO*, and the conversion of HCOO* are promoted by the addition of W. Based on the energetic span model, the turnover frequency (TOF) for the methanol synthesis from CO hydrogenation on the W-InO_D model is predicted as 9.0 × 10 s, which is much higher than the TOF of 4.5 × 10 s on the InO_D model. Overall, the introduction of tungsten makes the CO hydrogenation to methanol kinetically more favorable.
氧化铟是一种很有前景的用于将一氧化碳加氢制甲醇的催化剂，近年来已得到广泛研究。然而，关于掺杂氧化铟用于甲醇合成的研究相对较少，且钨掺杂氧化铟尚未见报道。在此，通过密度泛函理论（DFT）计算研究了在缺陷钨掺杂氧化铟模型（W-InO_D）上由一氧化碳加氢合成甲醇的机理。氧化铟催化剂上的氧空位对于一氧化碳的活化和转化至关重要。钨的引入导致氧空位上更高的电子密度和电子局域化，从而促进了一氧化碳的活化。W-InO_D模型上的甲醇合成通过甲酸途径经由HCO中间体进行。与InO_D模型相比，钨的添加促进了C-O键的断裂、HO的脱除以及HCOO的转化。基于能量跨度模型，预测W-InO_D模型上由一氧化碳加氢合成甲醇的周转频率（TOF）为9.0×10 s，远高于InO_D模型上4.5×10 s的TOF。总体而言，钨的引入使一氧化碳加氢制甲醇在动力学上更有利。
