胶原纤维接枝多酚负载钯-镍双金属催化剂的制备及其催化硝基苯的加氢性能

 以胶原纤维 (CF) 接枝表棓儿茶素棓酸酯 (EGCG) 为载体, 制备了新型 Pd-Ni/CF-EGCG 催化剂. EGCG 作为“桥分子”对 Pd-Ni 纳米粒子起着分散和锚定作用. 通过热重分析、扫描电镜、透射电镜、X 射线光电子能谱和 X 射线衍射对该催化剂进行了表征. 结果表明, 该催化剂具有规整的纤维结构, 在纤维表面形成了高分散的平均粒径为 2.2 nm 的 Pd-Ni 合金颗粒. 液相硝基苯催化加氢反应结果表明, 当 Ni 和 Pd 摩尔比为 0.8 时, Pd-Ni/CF-EGCG 催化剂具有最佳的双金属协同作用, 在 308 K 和 1.0 MPa 氢压下, 加氢速率达 237 min?1, 比单金属的 Pd/CF-EGCG 快 1 倍, 重复使用 5 次后仍具有较高的催化活性.

Preparation of Pd-Ni Bimetallic Catalyst Supported on Polyphenol-Grafted Collagen Fiber and Its Catalytic Behavior in Nitrobenzene Hydrogenation

A novel Pd-Ni bimetallic nanoparticle catalyst supported on epigallocatechin-3-gallate (EGCG) grafted collagen fiber (CF), Pd-Ni/CF-EGCG, has been prepared. EGCG was selected as a bridge molecule to anchor Pd-Ni nanoparticles and control the size and distribution of Pd-Ni nanoparticles. The morphology and physical properties of this catalyst were characterized by thermo-gravimetric analysis, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and X-ray diffraction. It was observed that this catalyst was in an ordered fibrous state, and well-dispersed Pd-Ni nanoparticles with an average diameter of 2.2 nm formed at the outer surface of CF. Hydrogenation of nitrobenzene catalyzed by Pd-Ni/CF-EGCG was investigated. An optimal synergistic action can be achieved when the molar ratio of Ni/Pd was 0.8, and the turnover frequency (TOF) was 237 min^-1 at 308 K and 1.0 MPa, which is twice as high as that of Pd/CF-EGCG. Pd-Ni/CF-EGCG still has higher activity after reuse five times.