摘要
制备系列K改性的β-Mo2C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β-Mo2C催化剂的c0加氢选择性发生显著变化。β-Mo2C催化剂CO加氢的产物主要为C1~C4烷烃,经K改性后β-Mo2C催化剂上产物主要为C1~C5低碳醇,其中高级醇(C2,OH)选择性可达到33.78%。通过对碱金属质量分数的考察发现,当K/Mo(原子比)为0.2时,总醇选择性达到最大值,低碳醇的时空收率达到0.12g/(mL·h^-1)。β-Mo2C催化剂上醇烃产物均符合线性Anderson-Schultz-Flory(A-S-F)分布曲线,而K改性β-Mo2C催化剂上醇产物为独特的甲醇负偏离A-S-F分布。可见,K助剂的加入有效促进了低碳醇的形成,尤其是促进了C1OH到C2OH的链增长步骤。
The modification effects of KECO3 on β-Mo2C catalysts for mixed alcohols synthesis from CO hydrogenation were studied. Un -promptedfl-MOEC produced mainly hydrocarbons of C1-C4 under the reaction conditions of 573 K, 8.0 MPa, H2/CO = 1.0, GHSV = 2 000 h^-1. Addition of KECO3 to β-Mo2C resulted in remarkable selectivity shift from hydrocarbons to alcohols. Moreover, the promoter of potassium enhanced the ability of chain propagation of β-Mo2C with the higher selectivity of C2+ alcohols. The investigations of the loadings of K2CO3 in β-Mo2C revealed that the maximum of alcohol yield obtained at K/Mo (molar ratio) =0.2. On K/β-Mo2C catalysts, the distribution of hydrocarbons obeyed the traditional linear Anderson - Schultz - Flory equation, while the distribution of alcohols gave a unique linear Anderson-Schultz-Flory with remarkable deviation of methanol. Thus, potassium promoter exerted a prominent function on the whole chain propagation to produce alcohols especially for the stage of methanol to ethanol.
出处
《燃料化学学报》
EI
CAS
CSCD
北大核心
2006年第2期200-204,共5页
Journal of Fuel Chemistry and Technology