谈薇,王玉琪,王金艳,郑岚,韩小龙,姚瑞清,周立发.K促进的Fe/椰壳炭催化剂对甲烷氮气常压合成氨性能的影响[J].分子催化,2015,(6):513-524
K促进的Fe/椰壳炭催化剂对甲烷氮气常压合成氨性能的影响
Promoting effect of potassium on the performance of iron/cocoanut-char catalyst in direct synthesis of ammonia from methane and nitrogen at atmospheric pressure
投稿时间:2015-06-18  修订日期:2015-12-09
DOI:
中文关键词:  钾促进  催化  椰壳炭  甲烷  常压合成氨
英文关键词:potassium promoting  catalysis  cocoanut-char  methane  ammonia synthesis at atmospheric pressure
基金项目:国家自然科学基金(21276209) ; 陕西省重大科技创新项目(2012ZKC03-1);国家自然科学基金项目(面上项目,重点项目,重大项目)
作者单位E-mail
谈薇 西北大学 tanwei0220@163.com 
王玉琪* 西北大学 wangyuqi@nwu.edu.cn 
王金艳 西北大学 877648579@qq.com 
郑岚 西北大学 21201987@qq.com 
韩小龙 西北大学 hxl9519@163.com 
姚瑞清 西北大学 yrqnwu@sina.com 
周立发 西北大学 zhoulf@nwu.edu.cn 
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中文摘要:
      采用等体积浸渍法制备了一系列催化剂用于甲烷氮气常压合成氨反应。对SiO2、γ-Al2O3、煤质柱状炭、椰壳活性炭为载体的Fe基催化剂的活性评价结果显示椰壳炭载体最优;通过对Zr、Ce、K等多种助剂的筛选,发现K促进的Fe基催化剂氨生成速率最高。利用XRD、SEM、BET等手段对载体和催化剂进行表征,结果表明椰壳炭具有规则孔道且孔容增大,催化剂还原后有新晶相KFeO2生成。最后在固定床微分反应器中,考察了常压合成氨催化剂的负载顺序及最优工况。结果表明,在常压700℃、V_(CH_4 )/V_(N_2 )=2/1、空速为2800mL/h时,催化剂3%K-5%Fe/椰壳炭的氨生成速率最高可达1.04×10-6mol•g-1•s-1,是现有文献值的83.5倍,将具有深远的工业应用前景。
英文摘要:
      A series of catalysts used for synthetic ammonia from methane and nitrogen at atmospheric pressure were prepared by the fractional wetness impregnation method. Based on the performance comparisons of iron catalysts among different supports, the coconut shell activated carbon displayed an excellent catalytic activity than SiO2, γ-Al2O3, and columnar carbon. Through the promoter selection experiments such as Zr, Ce and K, we found that the K promoted iron catalyst has the highest synthetic ammonia rate. XRD, SEM, and BET were carried out to characterize the supports and catalysts, and the results showed coconut shell activated carbon has the most uniform pore distribution with outstanding increase of average pore volume. A crystalline phase of KFeO2 was generated after the catalyst reduction. The optimal loading sequence and working conditions of synthetic ammonia catalysts were investigated in a fixed bed differential reactor. Experimental results prove that atmospheric pressure, 700 ℃, V_(CH_4 )/V_(N_2 )=2/1, flow rate of 2800 ml/h, 3%K-5%Fe /TC2 can achieve the most favorable synthetic ammonia rate of 1.04×10-6 mol•g-1•s-1, which is 83.5 times higher than current literature and would foresee an extensive prospects of industrial application in the future.
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