Co改性Mn/Cu/MgO催化剂对合成气制混合醇的影响

采用共沉淀法制备了Co改性的Mn/Cu/Mg氧化物催化剂,通过低温N2吸附-脱附、X射线衍射(XRD)、CO程序升温脱附(CO-TPD)、程序升温还原(H_2-TPR)和X射线光电子能谱分析(XPS)等手段对催化剂进行表征,并研究了其CO加氢制混合醇的催化性能。结果表明:Co的加入促进了Co_2Mg和MnCo_2O_4相的形成,有利于Cu,Mn及Mg物种的分散;当Co和Cu的物质的量之比增加至0.3时,总醇中C_(2+)OH与C_1OH选择性之比由0.31增至3.12,C_(2+)OH时空收率由9.07 g/(kg·h)增至28.83 g/(kg·h);适量Co助剂的添加可有效提高催化剂的插碳能力,从而提高了C_(2+)OH在总醇中的选择性,催化剂稳定性能良好。

Influence of Co Modified Mn/Cu/MgO Catalyst on the Synthesis of Mixed Alcohols from Syngas

Co modified Mn/Cu/MgO catalysts were prepared by co-precipitation method and were characterized by means of low-temperature nitrogen adsorption-desorption technique, X-ray diffraction(XRD), CO temperature-programmed desorption(CO-TPD), H2temperature-programmed reduce(H2-TPR), and X-ray photoelectron spectroscopy(XPS). The catalyst performance on the synthesis of mixed alcohols from syngas were investigated. The results indicated that Co2Mg and MnCo2O4 phase was formed, which facilitated the dispersion of the Cu, Mn and Mg species after adding the element of Co to Mn/Cu/MgO catalyst. Compared with the catalyst without Co, when the molar ratio of Co to Cu was 0.3, the selectivity ratio of C2+OH to C1OH and the space time yield of C2+OH increased from 0.31 to 3.12 and 9.07 g/(kg·h) to 28.83 g/(kg·h), respectively.The addition of promoter Co remarkably promoted the carbon insertion ability, which improved the selectivity of C2+OH in this reaction, and the catalyst showed high stability.