Preparation of supported Pt/CeO2-Al2O3 catalyst and its performance in the dehydrogenation of methylcyclohexane
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摘要: 通过超声辅助共沉淀法制备了具有高比表面积、大孔容和大孔径的CeO2-Al2O3复合载体, 并以此制备了一系列负载型Pt/CeO2-Al2O3催化剂, 采用XRD、氮吸附、NH3-TPD、SEM和TEM等方法对复合载体和催化剂进行了表征; 以甲基环己烷为模型化合物, 考察了Pt/CeO2-Al2O3催化剂的脱氢性能, 研究了载体中Ce/Al物质的量比及反应温度对其催化脱氢性能的影响。结果表明, 当Ce/Al物质的量比为0.5时, Pt/CeO2-Al2O3催化剂在450℃下具有较高的脱氢性能; 甲基环己烷转化率达到88.53%, 甲苯的选择性达94.63%。
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关键词:
- 氢能载体 /
- 脱氢 /
- CeO2-Al2O3复合载体 /
- 浸渍法 /
- 甲基环己烷
Abstract: Composite CeO2-Al2O3 oxides with high surface area, large pore volume and large pore diameter were prepared by ultrasonic co-precipitation; with CeO2-Al2O3 as the support, Pt/CeO2-Al2O3 catalysts were obtained by impregnation method. The supporter and the as-prepared Pt/CeO2-Al2O3 catalysts were characterized by XRD, NH3-TPD, nitrogen sorption and SEM; their catalytic performance in the dehydrogenation of methylcyclohexane as a model compound was investigated in a micro tube-reactor and the influences of Ce/Al (mol ratio) and reaction temperature on the dehydrogenation activity were considered. The results indicate that the Pt/CeO2-Al2O3 catalyst with a Ce/Al (mol ratio) of 0.5 performs best at 450℃ in the dehydrogenation of methylcyclohexane, with a methylcyclohexane conversion of 88.53% and a selectivity of 94.63% to toluene.-
Key words:
- hydrogen carrier /
- dehydrogenation /
- CeO2-Al2O3 composite support /
- impregnation /
- methylcyclohexane
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图 10 反应温度对MCH转化率和产物选择性的影响
Figure 10 Effect of reaction temperature on the methylcyclohexane conversion and selectivity to toluene over the 1%Pt/CeO2-Al2O3 catalysts with different Ce/Al mol ratios
(a): 1.0; (b): 0.5; (c): 2.0 (1-conversion of MCH; 2-selectivity to toluene; 3-selectivity to methylcyclohexene)
表 1 不同Ce/Al物质的量比复合载体CeO2-Al2O3的孔结构性质
Table 1 Textural properties of CeO2-Al2O3 composite supports with different Ce/Al mol ratios
Ce/Al
(mol ratio)Specific area
A/(m2·g-1)Pore volume
v/(mL·g-1)Pore diameter
d/nm1.0 100.0 0.41 12.12 0.5 102.0 0.46 9.60 2.0 47.0 0.19 9.59 -
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