三维介孔KIT-6上高分散Ni纳米粒子用于CO甲烷化:助剂对催化性能的影响（英文）
发布时间：2019-01-10 21:38
【摘要】：作为煤制天然气的核心技术之一,CO甲烷化工艺的开发基础便是高效催化剂的研制.目前,CO甲烷化催化剂主要采用Ni作为活性组分,但如何保持其具有较高的催化活性和优异的高温稳定性,仍为当今不得不面临的棘手问题.本文以乙二醇改性的三维介孔KIT-6为载体,利用其较高的比表面积、可调孔径、独特的双螺旋三维孔道结构等特点,通过湿式浸渍法成功制备了由助剂改性的Ni基催化剂,探讨了V,Ce,La,Mn等不同助剂对Ni基催化剂CO甲烷化催化性能的影响.分别采用X射线衍射、氢气程序升温还原、氢气程序升温脱附、傅里叶变换红外光谱、透射电子显微镜、能量色散X射线光谱、激光拉曼光谱和热重分析等手段对催化剂特性进行了表征.结果显示,Ni-V/KIT-6具有最高的Ni纳米粒子分散性(26.5%)和催化还原性,产生了最多的活性位,同时,Si O V的形成增强了金属-载体间相互作用,并因载体的三维介孔限制效应而形成较小Ni纳米粒子,这些均有助于提升Ni基催化剂CO甲烷化的催化性能和稳定性.在常压、250 400 ℃和60000mL/(g?h)空速的实验条件下对催化剂进行了催化活性评价测试.结果表明,助剂提高了CO甲烷化低温催化活性,其中,Ni-V/KIT-6在350 ℃的条件下实现了CO的完全转化,CH_4产率也高达85%;其在常压、500 ℃和60000 mL/(g?h)空速的操作条件下所进行的稳定性测试结果还显示,Ni-V/KIT-6也具有优异的抗烧结和抗积碳能力,展示了良好的高温稳定性.因此,Ni-V/KIT-6是一种具有广阔应用前景的CO甲烷化催化剂.
[Abstract]:As one of the core technologies of coal to produce natural gas, the development of CO methanation process is based on the development of high efficient catalyst. At present, CO methanation catalyst mainly uses Ni as active component, but how to maintain its high catalytic activity and excellent high temperature stability is still a thorny problem. In this paper, using ethylene glycol modified three-dimensional mesoporous KIT-6 as the carrier, using its high specific surface area, adjustable pore size and unique double helix three-dimensional pore structure, the Ni based catalyst modified by additives was successfully prepared by wet impregnation method. The effect of different promoters, such as V _ 2O _ ce _ La _ 2O _ mn and so on, on the catalytic performance of Ni based catalyst CO for methanation was investigated. X-ray diffraction, hydrogen temperature-programmed reduction, hydrogen temperature-programmed desorption, Fourier transform infrared spectroscopy, transmission electron microscope, energy dispersive X-ray spectroscopy, The characteristics of the catalyst were characterized by laser Raman spectroscopy and thermogravimetric analysis. The results show that Ni-V/KIT-6 has the highest dispersion of Ni nanoparticles (26.5%) and catalytic reduction, resulting in the most active sites. At the same time, the formation of Si O OV enhances the metal-carrier interaction. Smaller Ni nanoparticles were formed due to the three-dimensional mesoporous confinement effect of the support, which is helpful to improve the catalytic performance and stability of Ni based catalyst CO methanation. The catalytic activity of the catalyst was evaluated under the conditions of atmospheric pressure, 250,400 鈩，
本文编号：2406808
[Abstract]:As one of the core technologies of coal to produce natural gas, the development of CO methanation process is based on the development of high efficient catalyst. At present, CO methanation catalyst mainly uses Ni as active component, but how to maintain its high catalytic activity and excellent high temperature stability is still a thorny problem. In this paper, using ethylene glycol modified three-dimensional mesoporous KIT-6 as the carrier, using its high specific surface area, adjustable pore size and unique double helix three-dimensional pore structure, the Ni based catalyst modified by additives was successfully prepared by wet impregnation method. The effect of different promoters, such as V _ 2O _ ce _ La _ 2O _ mn and so on, on the catalytic performance of Ni based catalyst CO for methanation was investigated. X-ray diffraction, hydrogen temperature-programmed reduction, hydrogen temperature-programmed desorption, Fourier transform infrared spectroscopy, transmission electron microscope, energy dispersive X-ray spectroscopy, The characteristics of the catalyst were characterized by laser Raman spectroscopy and thermogravimetric analysis. The results show that Ni-V/KIT-6 has the highest dispersion of Ni nanoparticles (26.5%) and catalytic reduction, resulting in the most active sites. At the same time, the formation of Si O OV enhances the metal-carrier interaction. Smaller Ni nanoparticles were formed due to the three-dimensional mesoporous confinement effect of the support, which is helpful to improve the catalytic performance and stability of Ni based catalyst CO methanation. The catalytic activity of the catalyst was evaluated under the conditions of atmospheric pressure, 250,400 鈩，
本文编号：2406808
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