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摘要: 以Al2O3为载体, RuCl3·xH2O及Ni(NO3)2·6H2O为活性组分前驱体, 采用吸附-沉淀法制备系列Ru-Ni/Al2O3催化剂, 以马来酸二甲酯(DMS)催化加氢为探针反应, 考察了活化条件和Ni的添加量对催化剂性能的影响。随Ni负载量的升高, Ru-Ni/Al2O3催化剂活性呈现先升高后降低的趋势, 在Ni:Ru的原子比为6:1时(催化剂Ru1Ni6/Al)催化活性最高。催化剂Ru1Ni6/Al在氢气中200 ℃直接还原后的平均转化率与氢气中400 ℃还原后的平均转化率接近, 达到了单组分Ru/Al催化剂的1.5倍以上。XPS、XRD、H2-TPR数据表明, Ru与Ni之间发生了较强的相互作用, Ni的加入促进了金属Ru在载体上的分散, 提高了催化活性。
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关键词:
- Ru-Ni/Al2O3 /
- 催化加氢 /
- 马来酸二甲酯 /
- 丁二酸二甲酯
Abstract: A series of Ru-Ni/Al2O3 catalysts were prepared via adsorption-precipitation method, using Al2O3 as the support and RuCl3·xH2O and Ni(NO3)2·6H2O as precursors.Effects of pretreatment conditions and the amount of Ni on the catalytic behaviors of the catalysts were investigated.The catalytic activities of Ni-modified Ru catalysts increased with the increase of the Ni content firstly and then decreased.The highest hydrogenation activity was obtained as the atomic ratio of Ni:Ru is 6:1.The catalytic activity of Ru1Ni6/Al-fresh subjected to reduction at 200℃ has no significant difference with the sample reduced at 400℃, reaching to 1.5 times that of Ru/Al2O3 with the same pretreatment.Based on the results of XPS, XRD and H2-TPR, the reason for the promoted catalytic effect of Ni was disclosed.It was found that the dispersion of Ru could be improved as the promotion of Ni, resulting in the improvement of the catalytic performance of the Ru catalyst.-
Key words:
- Ru-Ni/Al2O3 /
- catalytic hydrogenation /
- dimethyl maleate /
- dimethyl succinate
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表 1 催化剂编号与预处理条件
Table 1 Catalyst codes and pretreatment conditions
Catalyst code Pretreatment procedure Ru/Al-fresh without pretreatment Ru1Ni1/Al-fresh without pretreatment Ru1Ni2/Al-fresh without pretreatment Ru1Ni4/Al-fresh without pretreatment Ru1Ni6/Al-fresh without pretreatment Ru1Ni8/Al-fresh without pretreatment Ni/Al-fresh without pretreatment Ru/Al-H Ru/Al-fresh reduced at 200 ℃ for 2 h in H2 Ru1Ni6/Al-H Ru1Ni6/Al-fresh reduced at 200 ℃ for 2 h in H2 Ru/Al-H1 Ru/Al-fresh reduced at 400 ℃ for 2 h in H2 Ru1Ni1/Al-H1 Ru1Ni1/Al-fresh reduced at 400 ℃ for 2 h in H2 Ru1Ni2/Al-H1 Ru1Ni2/Al-fresh reduced at 400 ℃ for 2 h in H2 Ru1Ni4/Al-H1 Ru1Ni4/Al-fresh reduced at 400 ℃ for 2 h in H2 Ru1Ni6/Al-H1 Ru1Ni6/Al-fresh reduced at 400 ℃ for 2 h in H2 Ru1Ni8/Al-H1 Ru1Ni8/Al-fresh reduced at 400 ℃ for 2 h in H2 Ni/Al-H1 Ni/Al-fresh reduced at 400 ℃ for 2 h in H2 表 2 还原活化催化剂上Ru/Al与Ni/Al的原子比
Table 2 Ru/Al and Ni/Al atomic ratios of the reduced catalysts
Catalyst code Ru/Al-H1 Ru1Ni6/Al-H1 Ni/Al-H1 Ru/Al
(atomic ratio)0.10 0.15 - Ni/Al
(atomic ratio)- 0.88 0.10 -
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