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采用共同浸渍法制备了K_2MoO_4-NiO/SiO_2催化剂,考察了NiO添加量对高硫合成气制甲硫醇K_2MoO_4/SiO_2催化剂性能的影响。活性评价结果表明,添加了NiO的催化剂活性有很大的提高,当Ni/Mo物质的量比为2/9时,CO转化率为72.6%,较未添加NiO的催化剂提高了一倍多。程序升温还原(TPR)表征显示,添加的NiO与Mo有强相互作用,促进了Mo物种的还原。电子自旋共振(ESR)表征显示,反应后的催化剂中可检测到“oxo-Mo(V)”物种和“thio-Mo(V)”物种,K_2MoO_4-NiO/SiO_2催化剂表面主要为“thio-Mo(V)”物种,而K_2MoO_4/SiO_2催化剂表面主要为“oxo-Mo(V)”物种,NiO的添加促进了Mo物种的还原、硫化,可能是造成催化剂活性极大提高的原因。
The K 2 MoO 4 -NiO / SiO 2 catalyst was prepared by the co-impregnation method. The effect of NiO dosage on the performance of the catalyst K 2 MoO 4 / SiO 2 was investigated. The results of the activity evaluation showed that the activity of the NiO-added catalyst greatly increased. When the Ni / Mo molar ratio was 2/9, the CO conversion was 72.6%, which was more than double that of the NiO-free catalyst. Temperature programmed reduction (TPR) characterization showed that NiO added strongly interacted with Mo and promoted the reduction of Mo species. Electron spin resonance (ESR) characterization revealed that the “oxo-Mo (V)” species and the “thio-Mo (V)” species were detected in the reacted catalyst and the surface of the K_2MoO_4-NiO / Is the species of “thio-Mo (V)”, while the surface of K_2MoO_4 / SiO_2 catalyst is mainly “oxo-Mo (V)”. The addition of NiO promotes the reduction and sulfidation of Mo species, Great reasons for improvement.