Ni-Cu作用对于1,4-丁炔二醇一步法低压加氢的影响

Effect of Ni-Cu on the one-step mild pressure hydrogenation of 1,4-butynediol

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Ni^2+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Ni^2+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。

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 Ni^2+ 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 Ni^2+ 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 Ni^2+ 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 Ni 0 active sites in the form of the high dispersion and the fitting acidity.