胶原纤维接枝多酚负载纳米钯的制备及其对硝基苯加氢的催化特性

以胶原纤维(CF)接枝表棓儿茶素棓酸脂(EGCG)为载体,制备了新型非均相钯(Pd)纳米催化剂(CF-EGCG-Pd).EGCG作为"桥分子"不仅对Pd纳米颗粒具有锚定作用,而且能控制Pd纳米颗粒的大小及分布.通过SEM、TEM、XRD、XPS对该催化剂的形貌和物理特性能进行了表征,发现该催化剂具有规整的纤维结构,在胶原纤维的外表面形成了高分散的平均粒径在3.8 nm的Pd纳米颗粒.将该催化剂用于硝基苯液相催化加氢反应,结果表明在308 K和1.0 MPa氢压下,硝基苯转化速率(TOF)达到34.13 mol·mol-1·min-1,苯胺选择性为100%,催化剂重复使用3次其催化活性基本不变.

Preparation of Pd nanoparticles supported by polyphenol-grafted collagen fiber and its catalytic hydrogenation behaviors of nitrobenzene

A novel palladium (Pd) nanoparticle catalyst stabilized by epigallocatechin-3-gallate (EGCG) grafted collagen fiber ( CF) has been prepared (CF-EGCG-Pd). EGCG was selected as a bridge molecule to anchor Pd nanoparticles and control the size and distribution of Pd nanoparticles. The morphology and physical properties of this novel catalyst fully characterized by means of SEM,TEM,XPS,and XRD. It was observed that this catalyst was in ordered fibrous state,and well-dispersed Pd nanoparticles with average diameter of 3.8 nm were formed onto the outer surface of CF. Hydrogenations of nitrobenzene catalyzed by CF-EGCG-Pd were investigated. It was found that at 308 K and 1.0 MPa hydrogen pressure, the turnover frequency (TOF) of nitrobenzene was up to 34.13 mol·mol~(-1) ·min~(-1) ,and the selectivity of aniline was 100%. The catalytic activity was almost no significant change after three times repeated application.