Mn Modified Ni/Bentonite for CO2 Methanation
Mn Modified Ni/Bentonite for CO2 Methanation
复制标题
用于 CO2 甲烷化的锰改性镍/膨润土
DOI：
10.3390/catal8120646
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发表时间：
2018-12-01
期刊：
影响因子：
3.9
通讯作者：
Ji, Hongbing
中科院分区：
文献类型：
--
作者：
Jiang, Yuexiu;Huang, Tongxia;Ji, Hongbing
为了提高Ni/膨润土催化剂的低温催化活性和稳定性，在Ni/膨润土催化剂中引入Mn，制备了Ni-Mn/膨润土催化剂，并将其用于CO2甲烷化反应。结果表明，Mn的加入增强了NiO与膨润土载体之间的相互作用，增加了活性组分Ni的分散度，减小了活性组分Ni的粒径，提高了Ni/膨润土催化剂的比表面积和孔容，减小了平均孔径，抑制了CO2甲烷化过程中Ni颗粒的聚集。同时，Mn的加入增加了Ni/膨润土催化剂表面的氧空位，促进了甲烷化反应中CO2的活化，提高了Ni/膨润土催化剂的低温活性和稳定性。在常压、270 ℃、V（H-2）：V（CO2）= 4、原料气空速3600 mL·g（cat）（-1）·h（-1）的反应条件下，在Mn含量为2wt%的Ni-Mn/膨润土催化剂上，CO2转化率为85.2%，CH 4选择性为99.8%。另一方面，当不添加Mn时，CO2转化率达到84.7%，并且反应温度仅升高至300 ℃。在150 h的稳定性试验中，Ni-2wt%Mn/膨润土催化剂的CO2转化率下降了2.2%，而Ni/膨润土催化剂的CO2转化率下降了6.4%。
To enhance the low-temperature catalytic activity and stability of Ni/bentonite catalyst, Ni-Mn/bentonite catalyst was prepared by introducing Mn into Ni/bentonite catalyst and was used for CO2 methanation. The results indicated that the addition of Mn enhanced the interaction between the NiO and the bentonite carrier, increased the dispersion of the active component Ni and decreased the grain size of the active component Ni, increased the specific surface area and pore volume of the Ni/bentonite catalyst, and decreased the average pore size, which suppressed the aggregation of Ni particles grown during the CO2 methanation process. At the same time, the Mn addition increased the amount of oxygen vacancies on the Ni/bentonite catalyst surface, which promoted the activation of CO2 in the methanation reaction, increasing the low-temperature activity and stability of the Ni/bentonite catalyst. Under the reaction condition of atmospheric pressure, 270 degrees C, V(H-2):V(CO2) = 4, and feed gas space velocity of 3600 mL.g(cat)(-1).h(-1), the CO2 conversion on the Ni-Mn/bentonite catalyst with 2wt% Mn was 85.2%, and the selectivity of CH4 was 99.8%. On the other hand, when Mn was not added, the CO2 conversion reached 84.7% and the reaction temperature only raised to 300 degrees C. During a 150-h stability test, the CO2 conversion of Ni-2wt% Mn/bentonite catalyst decreased by 2.2%, while the CO2 conversion of the Ni/bentonite catalyst decreased by 6.4%.