甲烷二氧化碳重整反应镍基和钴基催化剂的制备及性能研究

发布时间：2018-01-10 13:23

本文关键词：甲烷二氧化碳重整反应镍基和钴基催化剂的制备及性能研究　出处：《内蒙古大学》2015年硕士论文　论文类型：学位论文

【摘要】：甲烷二氧化碳重整反应可以有效地利用天然气和消除温室气体,对解决能源危机和改善气候环境问题具有广阔的应用前景而受到广泛关注。本文针对CH4/CO2重整反应催化体系,系统考察了活性组分、载体、助剂对催化性能的影响。本文采用初湿浸渍法制备了两种体系的CH4/CO2重整反应催化剂,通过XRD、N2吸附-脱附、化学吸附(H2-02滴定、H2-TPR)、SEM、TEM-EDAX、 TG-DTA等表征手段,分析了催化剂的物相组成、织构性质、金属分散度、还原性、形貌以及积炭等,考察了催化剂前驱体、活性组分负载量、载体对CH4/CO2重整反应活性及稳定性的影响,分别探究了同一载体不同活性组分对催化性能的影响。以介孔氧化铝为载体,制备了系列镍基催化剂x%Ni/OMA (x=5、0、15、20)和钴基催化剂x%Co/OMA (x=5、10、15、20),结果表明：金属分散度受活性金属负载量的影响,OMA表现出较强的金属-载体相互作用；常压、800℃C、空速为6000ml/g/h条件下反应20h,10%Ni/OMA的转化率和选择性均没有明显的下降,CH4和C02的转化率保持在98%、85%,H2/CO接近于1,催化活性较好。15%Co/OMA CH4和CO2的转化率分别在95%、35%,H2/CO接近1.2,积炭少催化活性较好,整体来看,10%Ni/OMA催化活性要高于15%Co/OMA。因为OMA显酸性,利于甲烷的吸附和活化,但不易于CO2的吸附和转化,于是采用Y2O3作为载体助剂,合成了介孔钇铝氧复合氧化物(YAG),以YAG为载体,制备了系列镍基x%Ni/YAG (x=5、10、15、20)和钴基催化剂x%Co/YAG (x=5.10、15、20)用于甲烷二氧化碳重整反应,研究发现：稀土钇的加入,提高了催化剂的金属分散度,降低活性组分的还原温度,增强催化剂的抗积炭性能,确定最佳反应温度为800℃。系列镍基催化剂中20%Ni/YAG积炭少,CH4、 CO2转化率分别达到95%、60%而积炭量较少,催化活性较好。15%Co/YAG的CH4、CO2转化率分别达到95%、60%而积炭量较少。相同反应条件下,20%Ni/YAG催化剂的催化性能好于15%Co/YAG。
[Abstract]:The carbon dioxide reforming of methane can effectively utilize the natural gas and the elimination of greenhouse gases, is to solve the problem of energy crisis and improve the climate and environment the broad application prospect and attracted widespread attention. In this paper CH4/CO2 catalytic reforming reaction system, investigated the active component and carrier, effect of additives on the catalytic performance. This paper uses the wet impregnation method preparation of two kinds of CH4/CO2 reforming catalyst by XRD, N2 adsorption desorption, chemical adsorption (H2-02 titration, H2-TPR, SEM, TEM-EDAX, TG-DTA) by means of analysis of the phase composition of the catalyst material texture properties, metal dispersion, reducibility, morphology and deposition, were investigated the precursor of the catalyst, the active component loading, carrier reaction activity and stability of CH4/CO2 reforming, respectively on the same carrier effect of different active component on the catalytic performance of mesoporous oxygen. Aluminum as the carrier, series of nickel based catalysts were prepared by x%Ni/OMA (x=5,0,15,20) and cobalt based catalyst x%Co/OMA (x=5,10,15,20), the results show that the metal dispersion affected by active metal loading, OMA showed strong metal support interaction; atmospheric pressure, 800 degrees C, space velocity of 6000ml/g/h reaction under the conditions of 20h. The conversion of 10%Ni/OMA and selectivity are not significantly reduced, CH4 and C02 conversion rate remained at 98%, 85%, H2/CO is close to 1, conversion of better catalytic activity and CO2.15%Co/OMA CH4 respectively in 95%, 35%, H2/CO is close to 1.2, the carbon deposit less good catalytic activity, overall, the photocatalytic activity is higher than 10%Ni/OMA 15%Co/OMA. because OMA is acidic, conducive to methane adsorption and activation, but not easy to adsorption and transformation of CO2, and using Y2O3 as carrier additives, mesoporous alumina synthesized yttrium oxides (YAG), with YAG as the carrier, the preparation of nickel series Based x%Ni/YAG (x=5,10,15,20) and x%Co/YAG (x=5.10,15,20) cobalt based catalyst for carbon dioxide reforming of methane reaction, the results showed that adding yttrium, improves the catalyst metal dispersion, reduce the reduction temperature of the active components, enhanced resistance to carbon deposition of the catalyst, the optimum reaction temperature is 800 DEG C. 20%Ni/YAG series of nickel based catalyst in less carbon deposition, CH4, CO2 conversion rate reached 95% and 60% respectively, the coke quantity is less, better catalytic activity of.15%Co/YAG CH4, CO2 conversion rate reached 95% and 60% respectively, the amount of coke deposited less. Under the same reaction conditions, the catalytic performance of 20%Ni/YAG catalyst was better than 15%Co/YAG.

【学位授予单位】：内蒙古大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE665.3;O643.36

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