共查询到18条相似文献,搜索用时 62 毫秒
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采用草酸盐胶态共沉淀-机械混合法制备了一系列Cu-Mn/γ-Al2O3催化剂,考察了CuMn摩尔比及助剂La、Al、Fe、Zn等对Cu-Mn/γ-Al2O3催化剂上二甲醚水蒸气重整制氢的催化性能的影响,并结合热重-差热扫描量热分析(TG-DSC)、N2吸附-脱附(BET)、X射线衍射(XRD)、H2程序升温还原(H2-TPR)等表征手段研究了助剂La的添加对Cu-Mn/γ-Al2O3催化剂微观结构的影响.研究表明:当Cu-Mn/γ-Al2O3催化剂中Cu/Mn摩尔比为1/2时,催化剂具有较高的初始活性;添加La、Al、Fe、Zn等助剂均不同程度地提高了Cu-Mn/γ-Al2O3催化剂的稳定性,其提高顺序为:La>Al>Fe>Zn;适量La的添加可以起到隔离和分散铜的作用,能阻碍活性组分的聚集长大,有助于活性组分细化,并增加表面高分散CuO的量,同时增强Cu-Mn以及金属铜和载体之间的相互作用,防止铜的团聚,从而提高催化剂的活性及稳定性. 相似文献
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La2O3改进Ni/γ-Al2O3催化剂上沼气重整制氢 总被引:1,自引:0,他引:1
为了寻求制备氢气的可再生资源及减少沼气的排放量,用浸渍法制备了不同La2O3含量的Ni/La2O3/γ Al2O3催化剂,用CH4/CO2体积比为1的混合气体模拟沼气,考察了还原温度、反应温度、空速等操作条件对该催化剂上沼气重整制氢性能的影响.并运用H2-TPR、TEM、TG-DSC等对催化剂进行了表征.结果表明:La2O3含量为6%的催化剂具有较好的综合性能;载体中掺杂适量La2O3能增加金属Ni的分散性,提高催化剂的可还原性及载体对CO2的吸附能力,从而改善了催化剂的活性及抗积炭性,使催化剂具有较好的稳定性.在100h的稳定性实验中,CH4及CO2转化率、H2及CO的选择性、H2/CO比平均值分别约为87.4%、88.8%、87.3%、93.8%及0.92.催化剂表面积炭速率非常低,仅为0.7279mg/(gcat·h). 相似文献
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采用溶胶–凝胶法结合湿浸渍法制备了Ni/ZrO2、Ni/La2O3-ZrO2和Ni/La2O3催化剂,采用XRD、BET、TG及 H2-TPR等方法对催化剂的结构和性质进行了表征。通过生物油模型物乙酸水蒸气重整反应,探讨了载体组成对催化剂性能和积炭形成的影响。载体组分不同的Ni催化剂具有不同的Ni颗粒尺寸、孔结构和Ni–载体相互作用,这对乙酸水蒸气重整反应路径有重要影响。催化剂Ni/70wt%La2O3-ZrO2在乙酸水蒸重整反应中表现出较好的催化性能和稳定性,在反应时间10 h内,氢气产率保持在76.05%以上;同时,TG和XRD分析结果表明,Ni/70wt%La2O3-ZrO2具有较好的抗烧结能力和较低的积炭率。 相似文献
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采用自制微型反应器和常规颗粒催化剂在常压、温度为450~550K、水醇比为1.1~1.3的条件下,通过沿反应通道控制催化剂颗粒梯级分布进行了甲醇水蒸气重整制氢的动力学测试。结果表明,重整产物中CO含量较低,可采用甲醇和水反应生成二氧化碳和氢气的单速率动力学模型;通过数据处理,得到如下动力学方程:rSR=3.72×1010exp(-1069762/RT)P0.C6H7302OHP0.3707H2O。F统计检验表明所得动力学模型的复相关指数大于0.9,且F统计量比置信域为99%的临界F统计量大10倍以上。所得动力学方程为实测中微型反应器的优化设计提供了数学模型基础。 相似文献
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选择乙酸作为生物质快速裂解油(生物油)的模型物,自制了一系列Ni基催化剂,进行水蒸汽催化重整制氢研究,实验结果表明Ni/Al_2O_3催化剂添加碱性氧化物MgO或(与)La_2O_3可以使得催化剂的活性有重大改善。Al_2O_3载体负载Ni金属后能够减缓碳的沉积速率,Ni/Al_2O_3添加MgO与(或)La_2O_3能够有效减少碳的沉积速率。选择催化剂Ni/MgO-La_2O_3-Al_2O_3以反应气中的H_2、CO、CH_4、CO_2产率为考察指标,考察反应温度、水碳比、进料流量对水蒸汽催化重整乙酸制氢反应的影响,获得较佳的条件为:反应温度为750~850℃,水碳摩尔比[W]/[C]为5~9,进料流量为15~25mL/h,H_2产率较高,大于80%。 相似文献
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以生物质气化模拟合成气H2/CO/N2为原料气,以堇青石蜂窝陶瓷为基体制备Ni/Al2O3整体式催化剂,通过扫描电镜(SEM)、比表面积(BET)、X射线衍射(XRD)、程序升温反应法(TPR)、热重分析(TG)等表征分析手段,考察催化剂制备方法(浸渍法和溶胶-凝胶法)、温度(250~550℃)及空速GHSV(6000~14000 mL/(g·h))对催化剂甲烷化性能的影响。结果表明:浸渍法制备的Ni/Al2O3催化剂(DIP-Ni/Al2O3)与溶胶-凝胶法制备的Ni/Al2O3催化剂(SGNi/Al2O3)相比,前者甲烷化性能较好。在H2、CO、N2物质的量之比为3∶1∶1且空速为10000 mL/(g·h)条件下,浸渍法制备的Ni/Al2O3催化剂在400℃时甲烷化性能最佳,且该条件下CO转化率为98.6%,CH4选择性为90.9%。当H2、CO、N2物质的量之比为3∶1∶1且温度为400℃时,在实验空速范围内,浸渍法制备的Ni/Al2O3催化剂CO转化率和CH4选择性均基本稳定在90%,甲烷化性能较好。 相似文献
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Fu Ming Qi Wei Zhang Zhikai Zhang Suping Yan Yongjie 《Energy Sources, Part A: Recovery, Utilization, and Environmental Effects》2016,38(14):2128-2134
Hydrogen production by steam reforming reaction of glycerol over Co/La/Ni-Al2O3 was studied in tubular fixed-bed reactor. The influences of operating parameters such as temperature, steam/carbon ratio, and weight hourly space velocity (WHSV) on hydrogen yield and carbon conversion were examined under atmospheric pressure. The results showed that carbon conversion increased with the increase of temperature and steam-to-carbon mole ratio (S/C). At 700°C, S/C=3:1, and WHSV=2.5h?1, hydrogen yield and potential hydrogen yield were up to 77.64% and 89.64%, respectively; meanwhile, the carbon conversion reached 96.36%. 相似文献
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《International Journal of Hydrogen Energy》2022,47(13):8177-8213
Hydrogen is contemplated as an alternative clean fuel for the future. Ethanol steam reforming (ESR) is a carbon-neutral, sustainable, green hydrogen production method. Low cost Ni/Al2O3 and Ni/CeO2 powder catalysts demonstrate high ESR activity. However, acidic nature of Al2O3 and instability of CeO2 lead to deactivation of the catalysts easily. This article examines the research articles published on the modification of Ni by various noble and non-noble metals and on alteration of the supports by different metal oxides in detail and their effect on ESR all through 2000–2021. The ESR reaction mechanisms on Ni/Al2O3 and Ni/CeO2 powder catalysts and basic thermodynamics for different possible reactions and H2 yield are explored. Manipulation of catalyst morphology (surface area and particle size) via preparation method, selection of active metal promoter and support modifier are found to be significantly important for H2 production and minimizing carbon deposition on catalysts. 相似文献
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Jiamin Wang Yan Sun Yujian Wu Xiaowen Shen Ren Tu Enchen Jiang Xiwei Xu 《国际能源研究杂志》2020,44(4):2754-2767
In this paper, three Ni/Al2O3 catalysts with different structure were prepared by different methods. The differences between the catalysts had been compared by H2 temperature program reduction (H2-TPR), X-ray diffraction, thermogravimetric analysis, scanning electron microscope, transmission electron microscope, and X-ray photoelectron spectroscopy. The results showed that synthesis method had significant effect on the combination of Ni particle with carrier. The method of coprecipitation could help to improve the combination of Ni and Al2O3, and the effect was further enhanced after adding polyethylene glycol (PEG). Due to the enhanced interaction between the active metal and the carrier, the NiO could be easily deoxidized and hard to sinter, which could obtain smaller and more dispersed Ni particles. Moreover, the addition of PEG improved the Ni particle size and its dispersion, and promoted the formation of the unique acicular Al2O3. The performance of guaiacol steam catalytic reforming via different catalysts was further analyzed, and the results showed the catalyst obtained by coprecipitation method with PEG exhibited best activity with 73.8% guaiacol conversion and 23.1 wt% H2 yield. 相似文献