TMCo-O催化剂结构调控及活化PMS降解双酚A的性能研究

Study on the Structure Regulation of TMCo-O Catalyst and the Performance of Activating PMS to Degrade Bisphenol A

摘要:

随着时代的发展，人类对塑料的高度依赖导致了双酚A （Bisphenol A, BPA）在水资源中重度积累，从而危及人类的身体安全。以过渡金属离子基催化剂活化过硫酸盐的高级氧化技术为处理双酚A的有效手段，通过调控锌、钴元素的掺杂比例，制备出具有金属有机框架结构的前驱体，再通过500 ℃高温煅烧，合成了锌钴双金属氧化物催化剂。此外，通过调控不同过渡金属掺杂，还制备了MnCo-Co-O和NiCo-Co-O催化剂。通过分析氧化物催化剂对双酚A的降解速率，研究不同锌、钴元素掺杂比例的催化剂及镍、锰元素掺杂的催化剂对过一硫酸盐（PMS）的活化能力，主要研究了不同锌钴元素掺杂比例的复合金属氧化物催化剂Co-Co-O、Zn-Co-O、ZnCo₂-Co-O和ZnCo-Co-O的催化性能。其中，锌钴掺杂比例为1∶2的双金属氧化物（ZnCo₂-Co-O）催化效果最好，催化效果的优化是基于锌钴离子之间产生的协同效应。同时，还研究了催化剂降解双酚A时的反应机理。结果表明，以羟基自由基（?OH）和单线态氧（¹O₂）为主要降解路径，可实现水体中有机污染物的高效去除。最后，研究了ZnCo₂-Co-O双金属氧化物催化剂在不同的阴离子环境下的催化性能，其中Cl^-的存在加快了强氧化基团的生成，SO₄^2-对催化剂不产生显著影响，而CO₃^2-会与强氧化基团发生不可逆反应而降低体系催化速率。本研究提供了一种新型过硫酸盐催化剂的改性策略，对于高效过硫酸盐催化剂的研发具有重要的意义。

关键词:双酚A;高级氧化;过一硫酸盐;钴基催化剂;锌钴双金属氧化物;协同效应;羟基自由基;单线态氧

Abstract:

With the time developing， the strong accumulation of bisphenol A （BPA） in water resources due to high reliance on plastics， while endangering human health. At present， the advanced oxidation technology of peroxymonosulfate （PMS） activated by transition metal-based catalyst has become an effective method to address BPA. The precursor with metal-organic framework structure was prepared by adjusting the doping ratio of zinc and cobalt elements， and further the zinc-cobalt bimetallic oxide catalyst was synthesized under 500 ℃ calcination. In addition， MnCo-Co-O and NiCo-Co-O materials were prepared by adjusting the doping of different transition metals. The activation ability of catalyst materials doped with zinc and cobalt， nickel and manganese to PMS was analyzed by the degradation rate of BPA. This work mainly studied the catalytic performance of four kinds of composite metal oxide catalysts with different zinc-cobalt doping ratio， among which the bimetallic oxide ZnCo₂-Co-O doped ratio of 1∶2 shows the best catalytic effect， and the optimization of catalytic effect is based on the synergistic effect between zinc and cobalt. The mechanism of catalytic degradation of bisphenol A was studied. Hydroxyl radical （?OH） and singlet oxygen （¹O₂） were used as the main degradation paths to achieve efficient removal of organic pollutants in water. Finally， the catalytic performance of ZnCo₂-Co-O bimetallic oxide catalysts in different anionic environments was studied. The presence of Cl^- accelerates the formation of strong oxidizing groups， no significant effect to catalytic performance by adding SO₄^2-， and CO₃^2- shows irreversible reaction with strong oxidizing groups to reduce the catalytic rate of the system. This work provides a new modification strategy， which is of great significance for the development of highly efficient PMS catalyst.

Key words:bisphenol A;advanced oxidation;peroxymonosulfate;cobalt-based catalyst;ZnCo-based bimetallic oxide;synergistic effect;hydroxyl radical;singlet oxygen