BaO对蒽醌氢化制过氧化氢Pd/Al_2O_3催化剂性能的影响

Effect of BaO on the Performance of Pd/Al_2O_3 Catalyst for H_2O_2 Production from Anthraquinone Hydrogenation

采用湿浸渍法制备了用于蒽醌氢化生产H2O2的含BaO的Pd/δ,θ-Al2O3系列催化剂,利用X射线衍射、扫描电镜、氮气物理吸附、氢-氧滴定和电子探针等技术手段考察了不同BaO含量对Pd/δ,θ-Al2O3催化剂性能的影响.结果表明,适量BaO的添加能抑制Al2O3的高温烧结,增大载体的比表面积,提高催化剂上金属Pd的分散度,减小Pd层厚度以及提高催化剂表面的Pd浓度,从而提高了催化剂的氢化活性.在钯负载量相同时,添加3%的BaO可使催化剂的活性提高25%左右.

A series of Pd/δ,θ-Al2O3 catalysts containing BaO for anthraquinone hydrogenation to produce H2O2 were prepared by the impregnation method. The effect of barium oxide on the performance of Pd/δ,θ-Al2O3 catalyst was investigated by X-ray diffraction, scanning electron microscopy, nitrogen adsorption, H2-O2 titra- tion, and electron probe microanalysis techniques. The results showed that barium oxide was a good promoter of the Pd/δ,θ-Al2O3 catalyst for the reaction. The addition of a proper amount of barium oxide could inhibit the growth of alumina crystals at high temperature, increase the catalyst surface area, improve the Pd dispersion, increase the Pd concentration on the catalyst surface, and decrease the Pd layer thickness. The addition of 3% BaO increased the catalyst activity by about 25 .