微乳法制备Pd-Cu双金属催化剂

选择Cu为助剂,采用微乳法分别优选具有较好稳定性的Cu和Pd微乳液体系,并将Cu和Pd依次负载于Al_2O_3载体上,经干燥、活化和还原制备了Pd-Cu/Al_2O_3催化剂。采用原位IR、CO化学吸附和HRTEM等对催化剂进行表征,结果表明,与常规溶液负载法制备的Pd-Ag/Al_2O_3催化剂相比,采用微乳法降低了催化剂表面酸性,提高了活性组分Pd分散度,Pd粒径分布更为均匀。在750 mL加氢反应器中,采用C_2后加氢原料对催化剂性能进行评价,结果表明,与常规溶液负载法相比,微乳法制备的催化剂在反应温度低4℃条件下,乙炔转化率相当,选择性高9.9个百分点,绿油生成量较低。微乳法制备Pd-Cu双金属催化剂具有良好的工业应用前景。

Preparation of Pd-Cu bimetallic catalysts by microemulsion method

Using Cu as the additive and optimizing Cu and Pd microemulsion systems with good stability,Pd-Cu/Al₂O₃ catalyst was prepared by microemulsion method,and then drying, activation and reduction.Pd-Cu/Al₂O₃ catalyst was characterized by means of in situ infrared, CO chemical adsorption analysis and HRTEM. The results showed that the acidity on the surface of the catalyst prepared by microemulsion method was reduced,and the as-prepared catalyst possessed better dispersion of active center and more uniform distribution of Pd particle size compared with the catalysts prepared by conventional solution load method. The performance of the catalyst was evaluated in a 750 mL carbon hydrogenation reactor by using C₂ post-hydrogenation raw material. The results indicated that the catalyst prepared by microemulsion method had the advantages of lower reaction temperature, similar acetylene conversion rate, higher selectivity and lower production amount of green oil compared with the catalyst prepared by the conventional solution load method. The reaction temperature was lower 4 ℃ and the selectivity was higher 9.9 percentage point than that on the catalysts prepared by the conventional solution load method. Pd-Cu bimetallic catalyst prepared by microemulsion method possessed good prospects of industrial application.