催化学报

催化学报 ›› 2011, Vol. 32 ›› Issue (7): 1250-1255.DOI: 10.3724/SP.J.1088.2011.10301

• 研究论文 • 上一篇    下一篇

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

吕兆坡, 唐浩东, 刘采来, 刘化章*   

  1. 浙江工业大学催化研究所, 浙江杭州 310032
  • 收稿日期:2011-03-01 修回日期:2011-04-15 出版日期:2011-07-18 发布日期:2014-11-28

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

LÜ Zhaopo, TANG Haodong, LIU Cailai, LIU Huazhang*   

  1. Institute of Industrial Catalysis, Zhejiang University of Technology, Hangzhou 310032, Zhejiang, China
  • Received:2011-03-01 Revised:2011-04-15 Online:2011-07-18 Published:2014-11-28

PDF

928

被引次数

15

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 4.6 mol/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%.

关键词: 合成气, 高碳醇, 活性炭, 钴, 锆, 镧, 硝酸, 酸性基团

Abstract: 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.

Key words: syngas, higher alcohol, activated carbon, cobalt, zirconium, lanthanum, nitric acid, acidic group