基于铁化合物的异相Fenton催化氧化技术

Iron Compound-Based Heterogeneous Fenton Catalytic Oxidation Technology

异相Fenton催化氧化技术是一种非常有效的处理难生物降解有机污染物的方法,它可以在温和的条件下实现反应。作为均相Fenton的发展,异相Fenton具有容易分离并再利用和更宽的适用范围等优点。该文主要综述了常见的含铁物质作为异相Fenton催化剂降解有机污染物的发展,这些催化剂包括零价铁、氧化铁、羟基氧化铁、水铁矿和其他铁化合物等。全面介绍了Fenton反应的不同机理,包括自由基机理和高价铁机理。重点讨论了提高异相Fenton催化剂活性的发展,并指出催化剂的效率受其表面氧化态、比表面积、过渡金属掺杂种类和晶相等许多因素的影响。概述了提高异相Fenton催化剂催化效率的不同方法,包括减小催化剂尺寸到纳米尺度、将催化剂负载于高比表面积载体上、引入过渡金属(如Ti、Co、Mn、Cr和V)到催化剂结构中。另外,一类新颖的异相Fenton催化剂铁氧体受到特别的关注,这是由于它高的催化活性和稳定性。最后,对异相Fenton催化氧化技术的发展进行了展望。我们认为理想的异相Fenton催化剂要具有高的催化活性和H2O2利用率、良好的稳定性、宽pH应用范围和易于回收利用等特点。

Heterogeneous Fenton catalytic oxidation technology is a powerful method for degradation of various kinds of non-biodegradable pollutants at moderate condition. Heterogeneous Fenton as the evolution of homogeneous Fenton reaction, offer the advantage of allowing easier separation from treated water and reuse, and wider field of application. This article mainly reviews the development of various iron-based materials, such as zero-valent iron, iron oxides, iron （hydr）oxides, ferrihydrite and other iron compounds, as heterogeneous catalysts for degrading organic pollutants. The mechanisms of Fenton reaction are comprehensively illustrated, including the free radical mechanism and the high-valent iron mechanism. Particularly, the emphasis is to summarize the catalytic activity of different heterogeneous Fenton catalysts, and point out that the catalytic efficiency of heterogeneous Fenton catalyst is strongly affected by the surface oxidation state, specific surface area, kinds of doped transition metal and the crystalline phase of catalysts. The different ways to improve the catalytic efficiency of heterogeneous Fenton catalysts are also concluded as： reducing the size of catalysts to nano-seales, loading the catalysts onto carriers with high specific surface area, introducing transition metal （such as Ti, Co, Mn, Cr and V） into the structure of ironoxide. In addition, some novel catalysts such as ferrites are especially paid attention due to their high catalytic activity and stability. Finally, the prospects of the development of the heterogeneous Fenton catalytic oxidation technology is given. We believe that an ideal heterogeneous Fenton catalyst should possess high catalytic efficiency and H202 utilization, good chemical stability, effectiveness at extend pH range and the ability of easy to be recycled.