原位聚合MnO_2/PoPD@PPS复合滤料及其NH_3-SCR脱硝性能研究

在聚苯硫醚(PPS)滤料表面包覆一层二氧化锰/聚邻苯二胺(PoPD)复合物。利用π-π共轭效应,将邻苯二胺(OPD)单体均匀吸附在PPS纤维表面,然后通过高锰酸钾溶液使邻苯二胺氧化聚合,在纤维表面原位生成聚邻苯二胺包覆层,同时高锰酸钾被还原成MnO_2催化剂,插入到聚邻苯二胺基体中。通过原位聚合生成的MnO_2/PoPD复合物与PPS滤料间有很强的黏结性,使得催化剂和滤料能牢固地结合在一起。该复合滤料制备方法简单,实验条件温和,对滤料本身性能没有损伤,通过FESEM、XPS、XRD、FT-IR、脱硝活性测试等对其结构和性能进行了研究。脱硝测试结果表明,KMnO4/PPS质量比为1∶1时,复合滤料在80-180℃下脱硝率可达36%-94%,10 h的催化剂稳定性测试中,其脱硝率在160℃下仍保持在88%;Mn 2p的XPS谱图证实复合滤料上催化剂为MnO_2;复合滤料的XRD谱图表明MnO_2为非晶结构;从FESEM照片可以看出,MnO_2催化剂在PPS滤料上分散均匀。

Preparation of MnO2/PoPD@PPS functional composites for low-temperature NO reduction with NH3

A layer of manganese dioxide/poly (p-phenylenediamine) (PoPD) complex was coated on the surface of polyphenylene sulfide (PPS). First, the o-phenylenediamine (OPD) monomer was uniformly adsorbed on the surface of the PPS fiber by the effect of π-π conjugation. Then, the o-phenylenediamine was oxidized by the potassium permanganate solution to produce poly (p-phenylenediamine) coat, while the potassium permanganate was reduced to MnO₂ catalyst and inserted into the poly (o-phenylenediamine) matrix. The MnO₂ catalyst was firmly bonded with the PPS filter because the MnO₂/PoPD complex formed by in-situ polymerization exhibited a strong bond with the PPS filter. The preparation method of MnO₂/PoPD@PPS composite filter was simple. Due to the mild experimental conditions, the performance of the PPS filter media was not damaged. The structure and properties of MnO₂/PoPD@PPS composite filter were studied in detail by FESEM, XPS, XRD, FT-IR and denitrification test. The results of denitration test show that the denitrification rate of MnO₂/PoPD@PPS composite filter increases with the increase of KMnO₄/PPS mass ratio. The optimum denitrification rate is 36%-94% at 80-180℃ with the KMnO₄/PPS mass ratio of 1:1, and it is 88% at 160℃ after 10 h catalyst stability test. The XPS spectrum of Mn 2p proves that the catalyst on the composite filter is MnO₂ that possesses amorphous structure observed from XRD patterns. It can be observed from the FESEM diagram that the dispersion of the MnO₂ catalyst on the PPS filter is uniform.