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研究以 (NH4 ) 6Mo7O2 4 ·4H2 O为前驱物料所制得的MoO3 /K2 CO3 /SiO2 催化剂对高硫化氢合成气一步法合成甲硫醇的催化活性 ,考察K2 CO3 助剂对钼基催化剂催化行为的影响。ESR表征结果显示 ,工作态催化剂观测到氧包围的“oxo -Mo(V)”(g =1.93)、硫包围的“thio -Mo(V)”(g =1.98)和S(g =2 .0 1,g =2 .0 4)等信号 ,随着K2 CO3 添加量的增加 ,oxo -Mo(V)含量增加 ,thio -Mo(V)含量减少 ;XPS表征显示 ,钼包含了Mo4 + 、Mo5+ 和Mo6+ 的混合价态 ,硫包含了S2 -(16 1.5eV)、(S -S) 2 -(16 2 .5eV)和S6+ (16 8.5eV)等 3种物种 ,Mo5+ /Mo4 + 摩比为 0 .4和S2 -/ (S -S) 2 -比接近 1有利于甲硫醇的生成
The catalytic activity of MoO3 / K2 CO3 / SiO2 catalyst synthesized from (NH4) 6Mo7O2 4 · 4H2O as the precursor to the one-step synthesis of methanethiol from high hydrogen sulfide synthesis gas was investigated. The catalytic effect of K2CO3 on molybdenum-based catalyst The impact of behavior. The results of ESR characterization showed that “oxo-MoO” (g = 1.93) and “thio-Mo (V)” surrounded by sulfur (g = 1.98) and S (g = 0, g = 2.04), the content of oxo-Mo (V) increased and the content of thio-Mo (V) decreased with the increase of K2CO3 addition. The mixed valence states of Mo5 + and Mo6 + include three kinds of species of S2 - (16 1.5eV), (S - S) 2 - (16 2 .5eV) and S6 + (16 8.5eV). Mo5 + / Mo4 + Of 0.4 and S2 - / (S - S) 2 - ratio close to 1 is favorable for the formation of methanethiol