Co修饰碳纳米管作为低碳醇合成CoMoK催化剂的高效促进剂  

Co-decorated MWCNTs as a Promoter of Co-Mo-K Catalyst for Synthesis of Higher Alcohols from Syngas

作　　者：武小满[1] 郭岩岩[1] 李辉[1] 林国栋[1] 张鸿斌[1] 

机构地区：[1]厦门大学化学化工学院化学系固体表面物理化学国家重点实验室,福建厦门361005

出　　处：《厦门大学学报（自然科学版）》2007年第4期445-450,共6页Journal of Xiamen University：Natural Science

基　　金：国家重点基础研究发展规划(973)项目(2005CB221403);国家自然科学基金项目(20473063;20590364);福建省科技重大项目(2005HZ01-3)共同资助

摘　　要：利用化学还原沉积法，制备一类Co修饰的多壁碳纳米管基复合材料（记为y％Co／MWCNT，y％为质量分数），进而用其作为促进剂，制备共沉淀型y％Co／MWCNT促进的Co-Mo-K氧化物基催化剂，CoiMOjKk-x％（y％Co／MWC-NT）（x％为质量分数）,实验发现，Co对MWCNT的预修饰明显地提高了单纯MWCNT促进的Co-Mo-K催化剂对CO加氢制低碳醇的催化活性,在所制备的Co1Mo1K0.05-12％（4．2％Co／MWCNT）催化剂上，在经优化的两种反应条件（5．0MPa，563K，V（H2）／V（CO）／V（N2）=60／30／10，GHSV=8000mL／（h·g）和5．0MPa，593K，V（H2）／V（CO）／V（COs）／V（N2）=60／30／5／5，GHSV=10000mL／（h·g））下，C2～9-醇的时空产率分别达294和628mg／（h·g），分别是单纯MWCNT促进的对应物在其最佳操作条件下这个值（269mg／（h·g））的1．09和2．33倍；在所制得两种低碳混合醇产物中，C2～9-醇的含量分别达89％和96％（质量分数），并分别以C7-醇和C5-醇为主要醇产物．本文结果表明，Co对MWCNT的预修饰并辅以原料合成气中添加适量CO2对于CO加氢转化率和C2～9-醇时空产率的显著提高起重要作用。Using chemical reduction-deposition method, a type of metallic cobalt-decorated multi-walled carbon nanotubes, noted as y% （mass percentage）Co/MWCNT,was prepared. Using the y%Co/MWCNT as promoter,a type of promoted Co-Mo-K oxide-based catalysts,noted as CoiMojKk-x%（y% Co/MWCNT）, for higher alcohol synthesis （HAS） was developed, h was experimentally shown that the Co-decorated MWCNT promoted catalyst displayed high activity for CO hydrogenation-conversion and excellent selectivity for formation of C2～9-alcohols. Over a Co1Mo1K0.05～12%（4.2%Co/MWCNT） catalyst, under the two types of reaction conditions,i, e. ,5.0 MPa,563 K,V（H2）/V（CO）/V（N2）=60/30/10,GHSV=8 000 mL/（h·g） and 5.0 MPa,593 K,V（H2）/V（CO）/V （CO2）/V（N2） = 60/30/5/5,GHSV=10 000 mL/（h·g）, the observed STY of C2～9-alcohols reached 294 and 628 mg/（h·g）, re- spectively; these were 1.05 and 2.33 times that （269 mg/（h·g）） of the sole MWCNT promoted counterpart, respectively, under its optimized reaction condition. The mass% of C2～9-alcohols reached 89% and 96% in the obtained two sorts of oxygenated products, with C7 and C5 alcohol as the main alcohol product,respectively,a good prospect for such oxygenated products to be used as gasoline additives. The results of the present work indicated that the Co-decorated MWCNTs could serve as an excellent promoter of the Co- Mo-K catalyst for HAS from syngas,and that the modification of Co to MWCNTs in combination of addition of a proper amount of CO2 into the feed syngas played an important role in promoting the enhancement of activity of CO hydrogenation-conversion and the improvement of the selectivity of higher alcohol synthesis.

关 键 词：Co修饰碳纳米管基复合材料 碳纳米管基促进剂 Co-Mo—K氧化物基催化剂 CO加氢 低碳醇合成 

分 类 号：O643.3[理学—物理化学]