Pd/g-C3N4对水中2,4-二氯酚的催化加氢脱氯研究

分别采用光沉积法和浸渍法制备了载钯石墨相氮化碳催化剂(Pd/g-C3N4-PD和Pd/g-C3N4-IMP),并对其进行了电感耦合等离子体发射光谱(ICP-AES)、X射线衍射(XRD)、透射电镜(TEM)和Zeta电位的表征.结果表明,不同载钯量Pd/g-C3N4-PD的等电点均在pH 2.3左右;Pd/g-C3N4-PD表面Pd粒子分散均匀,且Pd粒径小于Pd/g-C3N4-IMP.分别将Pd/g-C3N4-PD和Pd/g-C3N4-IMP用于2,4-二氯酚的催化加氢脱氯研究,Pd/g-C3N4-PD的催化脱氯效果明显优于Pd/g-C3N4-IMP.低pH值利于2,4-二氯酚的催化加氢脱氯过程,但不利于保持催化剂的稳定性.

Liquid phase catalytic hydrodechlorination of 2,4-dichlorophenol over Pd/g-C3N4

Graphitic carbon nitride supported palladium catalysts were prepared by photo-deposition method (Pd/g-C3N4-PD) and impregnation method (Pd/g-C3N4-IMP), respectively. The as-prepared catalysts were characterized by inductively coupled plasma-atomic emission spectrometry (ICP-AES), x-ray diffraction (XRD), transmission electron microscopy (TEM) and zeta potential measurement. The isoelectric points (IEPs) of Pd/g-C3N4-PD with different palladium load were around 2.3. The metallic Pd particles were uniformly dispersed on the surface of Pd/g-C3N4-PD catalyst, and the average Pd particle size on Pd/g-C3N4-PD was smaller than that of Pd/g-C3N4-IMP. Both Pd/g-C3N4-PD and Pd/g-C3N4-IMP catalysts were used in the liquid phase catalytic hydrodechlorination of 2,4-dichlorophenol. Results showed that Pd/g-C3N4-PD exhibited significantly higher catalytic activity than Pd/g-C3N4-IMP. Low pH was beneficial to the catalytic hydrodechlorination of 2,4-dichlorophenol, however, it did not benefit stability of catalyst.