【摘要】 制备K改性的α-MoC1-x催化剂并对其CO加氢合成低碳混合醇性能进行了考察。结果表明,K改性使α-MoC1-x催化剂的CO加氢选择性发生显著变化。α-MoC1-x催化剂CO加氢的产物主要为CO2和C1~4烷烃,同时有少量醇产物生成;经K改性后α-MoC1-x催化剂产物中烷烃选择性明显降低,而C1~5低碳醇选择性显著提高。通过对碱金属质量分数的考察发现,当K/Mo(摩尔比)为0.1时,总醇选择性达到极大值,低碳醇的时空收率达到28.6 g/(L.h)。α-MoC1-x催化剂上醇烃产物符合线性A-S-F分布曲线,K改性α-MoC1-x催化剂上醇烃产物也有类似A-S-F分布曲线,但K助剂的加入有效促进了低碳醇的形成及其链增长能力。结合XRD、SEM及XPS表征,K助剂与α-MoC1-x催化剂主体之间的电子作用导致其CO加氢产物选择性发生显著变化,这与K/α-MoC1-x催化剂表面“K-Mo-C”新相的生成有关。更多还原

【Abstract】 α-MoC_1-x,promoted by K₂CO₃,was studied as catalysts for carbon monoxide hydrogenation reactions under conditions of 573K,8.0MPa,GHSV=2000h^-1,n（H₂）/n（CO）=1.0.Unpromoted α-MoC_1-xproduced mainly CO₂ and light hydrocarbons,addition of K₂CO₃ as a promoter,however,resulted in remarkable selectivity shift from hydrocarbons to alcohols.Moreover,the promoter of potassium enhanced the ability of chain propagation of α-MoC_1-x with higher selectivity of C₂₊OH.The investigations of the effects of the loadings of K₂CO₃ in α-MoC_1-x revealed that the maximum yield of alcohols was obtained at K/Mo（mol ratio） =0.1.However,there was no significant difference between α-MoC_1-x and K/α-MoC_1-x catalysts in the distributions of alcohols and hydrocarbons;they both have similar linear A-S-F plots.Though,the promotion effects of potassium on the formation of higher alcohols could be attributed to the formation of "K-Mo-C" phase in K/α-MoC_1-x catalysts,which was considered to be the active sites for the alcohols synthesis.更多还原