Co和Zn改性H-MOR及其二甲醚羰基化反应性能

Co and Zn modified H-MOR and its performance of dimethyl ether carbonylation

采用水热合成法和离子交换法制备了H-MOR和金属改性的H-MOR(Co/H-MOR、Zn/H-MOR和Co-Zn/H-MOR)丝光沸石催化剂,并采用N2吸附/脱附、XRD、SEM、ICP-OES、NH3-TPD、TG和GC-MS等对催化剂进行了表征。在固定床反应器上考察了Co、Zn的添加及其负载量对催化剂的二甲醚羰基化反应性能的影响。结果表明,Co、Zn的掺入,增加了催化剂的酸量和酸强度,提高了催化剂的反应性能。在200℃、1.0 MPa和空速2040 mL/(g·h)的反应条件下,1Co-2Zn/H-MOR表现出最佳的反应性能,二甲醚转化率和乙酸甲酯选择性分别达到了58%和96%。Zn的引入抑制了催化剂上焦炭的沉积和软质焦炭向硬质焦炭的转化。随着Zn含量的增加,催化剂上焦炭含量和硬质焦炭比例明显减少。

H-MOR and metal modified H-MOR(Co/H-MOR,Zn/H-MOR and Co-Zn/H-MOR)were prepared by hydrothermal synthesis and ion exchange methods.The prepared catalysts were characterized by N2 adsorption/desorption,XRD,SEM,ICP-OES,NH3-TPD,TG and GC-MS.The influence of the Co and/or Zn loading and the loading amount on the reaction performance of the catalyst for carbonylation of dimethyl ether were investigated in a fixed bed reactor.The results showed that doped with Co and/or Zn increased the acid content and acid strength of the catalyst,and improved the reaction performance of the catalyst.Under the reaction conditions of 200℃,1.0 MPa and space velocity of 2040 mL/(g·h),1Co-2Zn/H-MOR exhibited the best catalytic performance,and the dimethyl ether conversion and methyl acetate selectivity were 58%and 96%,respectively.The introduction of Zn inhibited the deposition of coke on the catalyst and the conversion of soft coke to hard coke.With the increase of Zn loading,the coke content and the proportion of hard coke decreased significantly.