氧化铝对Fe-Cu-Zn-K-Al低碳醇合成催化剂性能的影响  

Effect of Alumina on Fe-Cu-Zn-K-Al Catalyst for Synthesis of Higher Alcohols

作　　者：苏运来[1] 刘云[1] 郭益群[1] 刘中民[2] 

机构地区：[1]郑州大学工业催化研究所,河南郑州450052 [2]中国科学院大连化学物理研究所,辽宁大连116023

出　　处：《催化学报》2003年第10期799-803,共5页

基　　金：河南省自然科学基金 (9740 3 110 0 );中国科学院山西煤炭化学研究所煤转化国家重点实验室基金(0 1/0 2年度 )资助项目

摘　　要：采用N2 吸咐 ,TPR和XRD等表征手段对高温熔融法制备的Fe Cu Zn K Al催化剂中氧化铝的作用进行了研究 .结果表明 ,当比表面积低于 4 0m2 /g时 ,催化剂性能受比表面积的影响非常明显 .少量的Al2 O3 即可有效地增加催化剂的比表面积 ,提高醇的收率和C2 +OH的选择性 ;大量的Al2 O3 虽然能使催化剂的比表面积有所增加 ,但醇的收率和C2 +OH选择性却显著降低 .这是Fe Cu Zn K Al催化剂中Al2 O3 同时具有物理作用和化学作用所致 .物理作用能有效地增加还原后催化剂的比表面积 ,提高金属利用率 ,分散催化剂的活性组分 ,使其更容易还原 ,进而提高催化剂活性和选择性 .化学作用影响到催化剂的电子性质 ,从而导致催化剂的活性和选择性降低 .TPR和XRD结果表明 ,在Fe Cu Zn K Al催化剂中 ,助剂Al2 O3 的作用随着其含量的变化而有所不同 .当Al2 O3 含量较低时 ,其物理作用是主要的 ;随着Al2 O3 含量的增加 ,其化学作用更为明显 ,甚至导致新物相AlFeO3 生成 。The influence of the contents of alumina on Fe Cu Zn K Al catalyst for synthesis of higher alcohols from synthesis gas was investigated. The reaction was carried out under the conditions of n (H 2) / n (CO) =2 3, φ (CO 2) =5 0%, little CH 4, SV= 5?000 h -1 , p =6 0 MPa and T =653 K. The catalytic performance of the catalyst is significantly affected by the specific surface area as it is below 4 0 m 2/g, and little Al 2O 3 can effectively increase the specific surface area of the catalyst. When increasing the amount of Al 2O 3 from 0 to 0 50% in the catalyst, the space time yield of higher alcohols increases from 0 44 to 0 62 g/(ml·h) , and the selectivity for C 2+ OH increases from 38 5% to 59 1%. However, the redundant Al 2O 3 (more than 5 00%) will obviously decrease the productivity of alcohols and the selectivity for C 2+ OH. This is because there are both physical and chemical effects of Al 2O 3 in the catalyst. The TPR and XRD results indicate that the role of Al 2O 3 is mainly physical effect when w (Al 2O 3)=0～0 50%, which can stabilize and disperse the active components, so that the modified Fe Cu Zn K Al can increase the space time yield of higher alcohols and the selectivity for C 2+ OH. In contrast, when w (Al 2O 3)>5 00%, the role of Al 2O 3 is mainly chemical effect. This is attributed to the interaction between Al 2O 3 and the other main component, by which a new phase of AlFeO 3 in the catalyst would be produced.

关 键 词：氧化铝 低碳醇 铁 铜 锌 钾 合成气 

分 类 号：O643.3[理学—物理化学]