碳纳米管负载镍催化剂的制备及其催化甲烷化性能研究

发布时间：2018-05-09 01:31

  本文选题：碳纳米管 + 金属镍　； 参考：《湖北工业大学》2017年硕士论文

【摘要】：碳纳米管(CNTs)因具有一系列优异的物理、化学特性已被广泛的应用在场发射、能源电池等领域,其同时也是一种性能优异的催化剂载体材料;甲烷化反应是将合成气转化成甲烷的重要过程,过程中采用的催化剂对甲烷化反应的进行非常重要;镍是一种资源丰富的金属元素,同时也是一种性能优异的甲烷化反应催化剂。因此本文拟以碳纳米管作为载体来负载金属镍,并对通过不同工艺制备的Ni/CNTs催化剂的结构及催化性能进行系统的研究,主要结论如下:(1)采用化学镀法、水热法、沉淀法以及浸渍法制备了Ni/CNTs催化剂,通过对制备过程的放大可行性以及所制备碳纳米管负载金属镍催化剂中金属镍颗粒的分散情况以及平均粒径进行综合考虑,认为采用浸渍法来制备Ni/CNTs更具有实际使用意义。(2)对采用浸渍法制备Ni/CNTs的过程进行系统的考察探索,发现CNTs的预处理过程、镍前驱体的选择、浸渍工艺以及热处理工艺对Ni/CNTs的催化性能影响较大,制备Ni/CNTs的最佳工艺条件为:碳纳米管预处理采用50 wt.%的硝酸进行回流处理、镍前驱体选择醋酸镍或者乙酰丙酮镍、浸渍时间选择为24小时至36小时、干燥过程选择40℃、60℃及红外光处理的三段干燥流程、焙烧温度为300℃,还原温度为500℃。(3)对在最佳制备过程下制备的Ni/CNTs的活性组分最佳负载量以及催化工艺条件进行了优化研究,其催化CO甲烷化的最佳镍负载量为14 wt.%,催化反应的最佳工艺为:原料气中n(H2)/n(CO)为3,反应温度为550℃、反应压力为4 MPa,反应空速为8000 h-1时,其催化活性最好,催化反应的CO2选择性较低,较好的抑制了CO甲烷化中的水煤气变换反应。
[Abstract]:Because of its excellent physical and chemical properties, CNTshas been widely used in field emission, energy battery and other fields. CNTsis also a kind of excellent catalyst carrier material. The methanation reaction is an important process of converting syngas to methane. The catalyst used in the process is very important for the methanation reaction; nickel is a resource-rich metal element. It is also an excellent catalyst for methanation. Therefore, carbon nanotubes (CNTs) are used as carriers to support nickel metal, and the structure and catalytic properties of Ni/CNTs catalysts prepared by different processes are systematically studied. The main conclusions are as follows: electroless plating method, hydrothermal method. Ni/CNTs catalysts were prepared by precipitation method and impregnation method. The feasibility of the preparation process and the dispersion and average particle size of nickel particles in the prepared carbon nanotube supported metal nickel catalyst were considered. It is considered that it is of practical significance to prepare Ni/CNTs by impregnation. (2) the process of preparing Ni/CNTs by impregnation is investigated systematically. It is found that the pretreatment process of CNTs and the selection of nickel precursor. The impregnation process and heat treatment process have great influence on the catalytic performance of Ni/CNTs. The optimum conditions for the preparation of Ni/CNTs are as follows: pretreatment of carbon nanotubes with 50 wt.% nitric acid refluxing, nickel precursor selection of nickel acetate or acetylacetone nickel, The impregnation time is 24 hours to 36 hours, the drying process is 40 鈩，

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