负载型铂催化剂催化氧化甲醛的研究进展

Research progress on catalytic oxidation of formaldehyde over supported platinum catalysts

建筑和装饰材料中缓慢释放的甲醛是一种主要的室内空气污染物,长期暴露在较低浓度的甲醛环境里会严重危害人类的身体健康。催化氧化法是一种非常有效的消除甲醛技术,能在较为温和的条件下将甲醛完全转化为二氧化碳和水。负载型铂催化剂对甲醛催化氧化反应表现出较为优异的催化性能,受到广泛研究和关注。本文综述了近年来该类催化剂的研究进展,主要探讨了制备方法、载体种类和形貌、添加助剂及反应条件参数等因素对负载型铂催化剂上甲醛催化氧化性能的影响;并归纳了一部分甲醛催化氧化的反应机理。分析认为:负载型铂催化剂在低温条件下具有很强的活化分子氧的能力,从而使其对甲醛低温催化氧化反应表现出很高的催化活性。另外还对负载型铂催化剂未来的研究发展方向进行了展望:应通过优化和改进催化剂制备方法和策略,提高铂原子的利用率,产生更多的表面/界面活性中心,继而进一步提高催化剂的性能;借助一些先进的表征技术如氧同位素示踪技术和理论计算的方法深入研究甲醛催化氧化反应机理等基础问题。

Formaldehyde(HCHO),emitted from buildings and decorative materials,is a major indoor air pollutant.Long-term exposure to low concentration of HCHO may cause serious health problems to human being.Catalytic oxidation of HCHO is one of the most effective approaches since it can completely convert HCHO into CO2and H2O at relatively mild operating conditions.Among numerous catalyst systems,supported platinum(Pt)catalysts have been extensively studied due to their superior catalytic performance for the oxidation of HCHO.In this paper,the recent progresses of the supported Pt catalysts in catalytic oxidation of HCHO have been summarized,and the main factors that influence the catalytic properties have been reviewed in terms of preparation methods,the types and the morphologies of the supports,the addition of promoters,as well as the reaction conditions.Besides,the reaction mechanisms for catalytic oxidation of HCHO over some supported Pt catalysts have also been summarized.It is believed that the outstanding ability of the supported Pt catalysts to activate oxygen molecules at low-temperature is mainly responsible for their excellent catalytic performance in low-temperature oxidation of HCHO.The opportunities for future research are as follows:to further enhance the catalytic activity of the supported Pt catalysts by improving the utilization of Pt atoms and producing more surface/interface active sites through optimizing catalyst preparation methods and strategies;to deeply reveal the reaction mechanisms for catalytic oxidation of HCHO over some representative supported Pt catalysts by combining some advanced characterization techniques like oxygen isotopic tracer technique and theroretical computations.