混合钴源对Co-Pd/TiO_2催化剂催化CH_4-CO_2两步梯阶转化法合成乙酸的性能影响

Catalytic Performances of Co-Pd/TiO_2 Catalysts Prepared with Mixed Cobalt Salts for Acetic Acid Synthesis from CH_4 and CO_2 by a Step-wise Reaction Sequence

以混合钴源为前驱体,采用等体积浸渍法制备了Co-Pd/TiO2催化剂,考察了其对CH4和CO2梯阶转化直接合成乙酸的催化性能,采用XRD,XPS,NH3-TPD和BET对催化剂进行了表征.结果表明,催化剂具有适宜的表面酸性、高比表面积和孔结构,有利于提高催化剂的活性.在m(CoCl2)∶m[Co(NO3)2]=2∶5,m(Co)∶m(Pd)=2∶1,常压,150℃条件下,乙酸的生成速率达到6.13 mg·g-1Cat·h-1,选择性达到81.6%,分别比以单一Co源制备的催化剂提高了134%和16%.

Co-Pd/TiO2 catalysts were prepared from mixed cobalt salts by incipient impregnation method.The catalytic performance of the catalysts for direct synthesis of acetic acid from CH4 and CO2 by a step-wise reaction technology was investigated.These catalysts were also characterized by XRD,XPS,NH3-TPD and BET.The results show that when the precursor is from mixed cobalt salts,a suitable surface acidity,high specific surface area and pore structure are formed,which favors the activity of catalysts.On the condition of m（CoCl2）∶ m[Co（NO3）2]=2∶ 5,m（Co）∶ m（Pd）=2∶ 1 and 150 ℃,the formation rate and selectivity of acetic acid reach 6.13 mg·g-1Cat·h-1and 81.6%,respectively.Compared with the catalysts prepared from single cobalt,the rate and selectivity increase by 134% and 16%.