海绵铁三金属降解对硝基苯酚的影响因素及催化机理

通过超声置换反应制备钯铜共修饰海绵铁三金属催化剂（Pd-（Cu-s-Fe⁰）），研究了三金属负载顺序、金属负载量、材料投加量以及重复利用对材料降解对硝基苯酚（PNP）的影响，并利用扫描电子显微镜（SEM）和X射线光电子能谱（XPS）表征材料表面结构特征.结果表明，Pd-（Cu-s-Fe⁰）催化活性高于Cu-（Pd-s-Fe⁰）和（Cu-Pd）-s-Fe⁰；Cu和Pd的最佳负载量分别为5%和0.025%.在100mL初始浓度为100mg/L的PNP溶液中投加3g Pd-（Cu-s-Fe⁰）并超声反应30min，PNP的降解率超过80%，降解反应基本符合一级动力学方程；Pd-（Cu-s-Fe⁰）材料循环利用4次表现出良好的循环利用性能.此外，PNP的主要催化还原产物是对氨基苯酚（PAP），主要的反应路径是催化还原反应.

Study on influencing factors and catalytic mechanism of p-nitrophenol degradation with sponge iron-based tri-metals

Pd-(Cu-s-Fe⁰) trimetals were synthesized adopting with displacement reactions under ultrasonic conditions, and the surface structure of the aforementioned materials was further characterized with scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). Moreover, the effects of noble metal loading sequence, the loading amount, input dosage and recycling reuse for the degradation of p-nitrophenol (PNP) was studied in detail. The experimental results show that the catalytic activity of Pd-(Cu-s-Fe⁰) was higher than that of Cu-(Pd-s-Fe⁰) and (Cu-Pd)-s-Fe⁰. The loading amounts of Cu and Pd were optimized as 5% and 0.025%, respectively. Under the optimized conditions including 30g/L of Pd-(Cu-s-Fe⁰), the removal content of PNP (100mL, initial concentration of 100mg/L) reached more than 80% after 30min of ultrasonic reactions, and the degradation reactions conformed to a pseudo-first-order kinetics equation. Furthermore, after 4times of recycling tests, Pd-(Cu-s-Fe⁰) showed good recycling performance. Based on the UV-visible spectral variations and high-performance liquid chromatography, we proposed the degradation mechanism mainly via catalytic reductions of PNP into p-aminophenol (PAP).