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以柠檬酸(CA)为络合剂,采用溶胶-凝胶法制备了K/Fe/β-Mo2C催化剂前驱体,将该前驱体在Ar气氛下程序升温碳化制备了纳米尺寸的K/Fe/β-Mo2C催化剂。考察了K含量对K/Fe/β-Mo2C催化剂织构及CO加氢反应性能的影响。结果表明,K助剂的引入促进了催化剂中β-Mo2C晶粒的长大,适量的K提高了催化剂的比表面积,提高了催化剂的活性和低碳醇选择性,但是过量K助剂的引入在催化剂表面形成了惰性的K2MoO4和K2Mo2O7,覆盖了部分活性中心,降低了催化剂的活性和低碳醇选择性。
K / Fe / β-Mo2C catalyst precursors were prepared by sol-gel method using citric acid (CA) as complexing agent and the precursor was heated and carbonized under Ar atmosphere to prepare nano- β-Mo2C catalyst. The effects of K content on the texture and CO hydrogenation performance of K / Fe / β-Mo2C catalysts were investigated. The results showed that the introduction of K promoter promoted the growth of β-Mo2C grains in the catalyst. The appropriate amount of K increased the specific surface area of the catalyst and increased the activity of the catalyst and the selectivity of the lower alcohol. However, the introduction of excess K promoter The formation of inert K2MoO4 and K2Mo2O7 on the catalyst surface, covering part of the active center, reducing the catalyst activity and lower alcohol selectivity.