Cu-ZnO双反应中心类芬顿催化剂降解水中碘乙腈性能与机制

多相芬顿催化虽然克服了均相芬顿pH适用范围窄，铁泥二次污染等问题，但还面临着稳定性差，H₂O₂利用率低的问题，从而限制了其实际应用。本文利用锌和铜的电负性差异制备了一种双反应中心催化剂Cu-ZnO，通过在催化剂表面构建贫富电子中心，从而诱导H₂O₂产生·OH降解污染物。采用TEM、EDS、XRD、FTIR、XPS以及EPR对催化剂进行表征，并研究了催化剂投加量、H₂O₂投加量、pH以及共存离子对碘乙腈降解效果的影响。结果表明，在催化剂投加量为1 g·L^-1，双氧水投加量为10 mmol·L^-1时，Cu-ZnO对碘乙腈的去除率在91%。大部分共存离子对催化剂的降解效果影响较小，且在酸性条件下催化剂稳定性较好，中性和碱性条件下金属离子基本无释放。催化剂诱导产生的•OH和HO₂^•/O₂^•−是碘乙腈(IAN)降解的主要活性物种，降解产物包括CO₂，H₂O，I^－和IO₃^- 等。

Catalytic oxidation of iodoacetonitrile by Cu-ZnO dual-reaction center catalyst in water and its mechanism

The practical application of heterogeneous Fenton catalysis was limited by the instability and inefficiency of H2O2, even though which overcomes the problems such as narrow pH range and secondary pollution of iron sludge compared to homogeneous Fenton. In this study, a dual-reaction center catalyst Cu-ZnO was developed by taking advantage of the electronegativity difference between zinc and copper, and the rich and poor electron centers were constructed on the surface of the catalyst which could induce H2O2 and produce •OH for pollutants degradation. The catalysts were characterized by TEM, EDS, XRD, FTIR, XPS and EPR, and the effects of dosage of catalyst and H2O2, pH and coexisting ions on the degradation of iodoacetonitrile(IAN) were investigated. The results showed that 91% IAN was removed when the dosages of catalyst and H2O2 were 1 g·L-1 and 10 mM, respectively. Most coexisting ions had slight effects on IAN degradation by Cu-ZnO which showed a better stability under acidic conditions, and no metal ions released at neutral and basic pHs. •OH and HO2•/O2•− induced by catalyst are the main active species for IAN degradation, the degradation products included CO2, H2O, I－, IO3－ and other organic products.