Various formulations of Co, Ni and K modified MoS₂-based catalysts were synthesized hydrothermally and compared in their catalytic performance in CO₂ hydrogenation at 21 bar and 220 C–330 C. The products were CO, CH₄ and methanol. The addition of K reduced the selectivity to CH₄ and moved the maximum of the methanol formation rate to a higher temperature. The materials were characterized by N₂ physisorption, temperature programmed oxidation, temperature programmed reduction, and x-ray diffraction spectra (XRD). Under reducing conditions the catalysts were stable until 700 C and under oxidizing conditions until 300 C. XRD had shown mainly a MoS₂ phase, as well as metal sulfide in the cobalt and nickel promoted catalysts. Different species of Mo and O were observed under reaction conditions by in situ x-ray photoelectron spectroscopy (XPS). When switching from H₂ to CO₂ + H₂ an increase in the amount of oxygen, both lattice oxygen and surface adsorbates, was observed as a consequence of CO₂ addition and H₂O formation in the reaction. The amount of lattice oxygen correlates with the minor amount of Mo(VI) detected. Increasing reaction temperature and thus conversion led to an increase of the O 1s signals at 533 eV assigned to surface OH, formate and adsorbed H₂O. XPS measurements in CO₂ + H₂ feed showed an effect of K addition on the adsorbate-related O 1s peak, which appeared at lower binding energy (532 eV) and was assigned to carbonates. This may indicate a different reaction mechanism in the presence of the promoter.

水热合成了Co、Ni 和K 改性MoS ₂基催化剂的各种配方，并在21 bar 和220 C–330 C 条件下比较了它们在CO ₂加氢中的催化性能。产物为CO、CH ₄和甲醇。K 的加入降低了对 CH ₄的选择性并将甲醇形成速率的最大值移至更高的温度。通过N ₂物理吸附、程序升温氧化、程序升温还原和X射线衍射光谱(XRD)对材料进行表征。在还原条件下，催化剂稳定到 700℃，在氧化条件下稳定到 300℃。XRD 显示主要是 MoS ₂相，以及钴和镍促进的催化剂中的金属硫化物。通过原位X 射线光电子能谱 (XPS)在反应条件下观察到不同种类的 Mo 和 O。当从H ₂转换为CO ₂ + H _{2 时}，观察到由于CO ₂添加和反应中H ₂ O形成的结果，氧的量（晶格氧和表面吸附物）增加。晶格氧的量与检测到的少量 Mo(VI) 相关。提高反应温度和转化率导致分配给表面 OH、甲酸盐和吸附的 H ₂ O 的533 eV 的 O 1s 信号增加。CO _{2 中的}XPS 测量+ H ₂进料显示出 K 添加对与吸附物相关的 O 1s 峰的影响，该峰出现在较低的结合能 (532 eV) 并被指定为碳酸盐。这可能表明在促进剂存在下不同的反应机制。