酸处理活性炭对其负载的Co-Zr-La催化剂上CO加氢制高碳醇反应性能的影响  

Effect of Acid Pretreatment of Activated Carbon (AC) on Catalytic Performance of Co-Zr-La/AC Catalysts for Higher Alcohols Production from Syngas

作　　者：吕兆坡[1] 唐浩东[1] 刘采来[1] 刘化章[1] 

机构地区：[1]浙江工业大学催化研究所,浙江杭州310032

出　　处：《催化学报》2011年第7期1250-1255,共6页

摘　　要：以不同浓度硝酸处理的活性碳(AC)为载体,制备了Co-Zr-La/AC催化剂,并考察了其催化CO加氢制备高碳醇(C6以上)的反应性能.通过Boehm滴定法和N2物理吸附考察了各AC的表面性质,并采用CO化学吸附、程序升温还原和X射线衍射对催化剂进行了表征.结果表明,经硝酸处理后,AC表面酸性基团(如羧基和内酯基)的数量增加,同时催化剂样品上Co和Co2C晶相衍射峰强度也发生变化,从而使催化剂上CO转化率从9.9%提高到65.3%,但醇选择性从62.3%降低到40.5%.当用4.6mol/L硝酸处理AC时,相应催化剂上的金属态Co和Co2C的比例较为适宜,从而提高了高碳醇在醇中的分布,达40.3%.Activated carbon（AC） was treated with nitric acid of different concentrations prior to the preparation of Co-Zr-La/AC higher alcohol synthesis catalysts. The effect of acid pretreatment on the catalyst activity was studied. The surface properties of the samples were investigated by Boehm titration and N2 physisorption. And the Co dispersion,reduction properties,and physical structure of the catalysts were characterized by CO chemisorption,temperature-programmed reduction,and X-ray diffraction（XRD） ,respectively. The results show that the nitric acid pretreatment causes the surface oxygen groups on the AC surface increase significantly and the XRD peak intensities of Co and Co2C in the catalysts vary dramatically. As a result,CO conversion increases from 9.9% to 65.3%,and the selectivity for total alcohol decreases from 62.3% to 40.5%. Although total alcohol selectivity decreases after the pretreatment,the selectivity for C6＋ alcohols increases from about 12.6% to 40.3% when there are suitable amounts of Co and Co2C active sites in the catalyst that is treated with 4.6 mol/L nitric acid.

关 键 词：合成气 高碳醇 活性炭 钴 锆 镧 硝酸 酸性基团 

分 类 号：O643.36[理学—物理化学]