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摘要: 采用沉积沉淀法将金属助剂引入Ni/Al2O3催化剂，考察不同金属助剂对于BYD加氢体系的影响，进一步优选助剂的最佳含量，并结合BET、XRD、H2-TPR、EDX-MAPPING、TEM、XPS、NH3-TPD等表征手段对催化剂物化性质进行研究。结果表明，金属助剂的添加主要影响了活性组分与载体间相互作用，成为影响催化活性的主要原因。Cu与Fe的引入使催化剂中Ni2+与载体之间相互作用明显减弱，提高了还原性能，BYD转化率提高至95%。通过考察优选金属助剂Cu含量对于催化剂物化性质的影响，发现使Ni2+与载体间相互作用力减弱的主要原因在于Cu表面氢溢流现象，然而，较多还原后的Ni颗粒由于与载体间的弱相互作用，易发生团聚，对加氢过程造成不利影响，通过Ni-Cu金属作用可有效地将金属固定于在载体表面，避免粒子迁移、团聚，Cu添加量5%时，催化剂凭借较多分散度良好的活性组分和适宜酸性，最终表现出最优加氢性能。
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关键词:
- Ni/Al2O3催化剂 /
- Ni-Cu作用 /
- 改性 /
- 1, 4-丁炔二醇 /
- 1, 4-丁烯二醇
Abstract: The deposition-precipitation method was employed for the purpose of bringing in metallic promoters into Ni/Al2O3 catalysts. The effects of various metallic promoters on the catalytic performance in 1, 4-butynediol (BYD) hydrogenation were investigated. Besides, the contents of the suitable promoter were further studied, which were combined with BET, XRD, H2-TPR, EDX-MAPPING, TEM, XPS, and NH3-TPD techniques, aimed at exploring physico-chemical characteristics in catalysts. As the findings suggested, the addition of different promoters substantially impacted the interaction between Ni2+ and support, acting as the key factor impacting the catalytic performance. The introduction of Cu and Fe had the potential to prominently lower the strong interaction between Ni2+ and support for the improvement of the BYD conversion of 95%. Furthermore, different contents of Cu were further studied and discovered that it was the phenomenon of hydrogen spillover arisen on Cu surfaces, efficiently lowering the interaction between Ni2+ and support. Nevertheless, the aggregation in Ni particles cannot be evitable, but for the existence of Ni-Cu alloying in Cu-added catalysts. As the Cu content reached up to 5%, the catalyst manifested the excellent catalytic performance in hydrogenation owing to the abundant amount of Ni0 active sites in the form of the high dispersion and the fitting acidity.-
Key words:
- Ni/Al2O3 catalysts /
- Ni-Cu /
- modification /
- BYD /
- BED
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图 1 催化剂加氢过程装置示意图
Figure 1 Simplified schematic diagram of hydrogenation process device
图 3 还原后的不同Nx03催化剂的N2吸附-脱附曲线(a)和相应孔径分布(b)
Figure 3 Nitrogen adsorption-desorption isotherms of different Nx03 catalysts (a) and corresponding distribution of pore sizes (b) after reduction
图 4 还原后不同Nx03催化剂的XRD谱图
Figure 4 XRD patterns of different Nx03 catalysts after reduction
图 6 还原后不同催化剂的NH3-TPD谱图
Figure 6 NH3-TPD profiles of different Nx03 catalysts after reduction
图 8 不同Nx03催化剂的BYD选择性
Figure 8 Catalytic performances of different Nx03 catalysts in selective hydrogenation of BYD process
:BED; : HTHF; : BDO; : others
图 9 还原后不同NCy催化剂的N2吸附-脱附曲线(a)及孔径分布(b)
Figure 9 Nitrogen adsorption-desorption isotherms of the NCy catalysts (a) and corresponding distribution of pore sizes (b) after reduction
图 12 还原后NC05催化剂的EDX-MAPPING照片
Figure 12 EDX-MAPPING images of the NC05 catalyst after reduction
图 13 还原后不同NCy催化剂的TEM照片(100000×)
Figure 13 TEM images with 100000× magnification of the NCy catalysts after reduction
图 14 金属助剂Cu的作用机制示意图
Figure 14 Schematic diagram of action mechanism over the Ni based catalyst with Cu promoter
图 16 还原后不同NCy催化剂的NH3-TPD谱图
Figure 16 NH3-TPD profilesof the NCy catalysts after reduction
图 17 不同NCy催化剂的BYD选择性
Figure 17 Catalytic performances of the NCy catalysts in selective hydrogenation of BYD process
:BED; : HTHF; : BDO; : others
表 1 不同Nx03催化剂的织构参数
Table 1 Textural properties of different Nx03 catalysts
Catalyst ABET/(m2·g-1) vp/(cm3·g-1) Dp/nm DNia/nm N00 154.28 0.54 14.00 9.0 NZ03 147.09 0.52 14.16 8.3 NM03 148.52 0.53 14.22 7.9 NF03 147.37 0.52 14.25 12.1 NC03 146.68 0.52 14.09 11.5 a: the mean sizes of nickel crystallites were determined from the broadening of the Ni (111), according to the Scherrer-Warren equation 
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表 2 不同NCy催化剂的织构参数
Table 2 Textural properties of different NCy catalysts
Catalyst ABET/(m2·g-1) vp/(cm3·g-1) Dp/nm N00 154.28 0.54 14.00 NC03 146.68 0.52 14.09 NC05 140.24 0.50 14.17 NC08 134.60 0.48 14.23 NC10 128.97 0.47 14.56 NC12 123.81 0.46 14.89
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表 3 还原后不同NCy催化剂的XPS分析
Table 3 Detailed XPS results of the NCy catalysts after reduction
Catalyst Ni peak area ratio /% Cu peak area ratio /% Ni0 Ni2+a Ni2+b satellite Cu0/Cu+ Cu2+ satellite NC00 9.5 39.8 25.2 25.5 - - - NC03 9.6 44.9 16.1 29.4 48.9 51.1 - NC05 12.9 48.0 10.7 28.4 53.9 46.1 - NC08 13.5 45.0 13.0 28.5 58.0 27.7 14.3 NC10 14.7 40 14.0 31.3 60.3 27.2 12.5 NC12 15.1 47.4 7.0 30.5 62.0 24.3 13.7 a: Ni2+ weakly interacting with support; b: Ni2+ strongly interacting with support
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