Zhu Xiaofeng, Yu Jiaguo, Jiang Chuanjia, Cheng Bei
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan, 430070, China.
Phys Chem Chem Phys. 2017 Mar 8;19(10):6957-6963. doi: 10.1039/c6cp08223h.
To overcome the drawbacks of powder-like catalysts in practical application, an AlO molecular sieve supported Pt (Pt-AlO) catalyst was prepared by the impregnation method combined with dilute hydrochloric acid solution pretreatment. The role of the pretreatment solution in catalyst preparation and formaldehyde (HCHO) decomposition over Pt-AlO catalysts was investigated. The acid solution with pH = 1 was optimal for Pt dispersion on the AlO surface. The Pt-AlO catalyst was capable of achieving complete and stable HCHO oxidation at ambient temperature. In addition, the excellent activity for HCHO removal was promoted by the mesoporous structure, large specific surface area and high adsorption ability of AlO molecular sieves, as determined by N-sorption studies. Dioxymethylene (DOM) and formate species were identified as major intermediates by in situ DRIFTS studies. These intermediates were subsequently oxidized into CO and HO at ambient temperature. Moreover, a possible reaction mechanism of HCHO removal and a regeneration pathway of surface hydroxyls were proposed. This study provides new insights into the preparation of practical, low-cost catalysts for indoor air purification.
为克服粉末状催化剂在实际应用中的缺点，采用浸渍法结合稀盐酸溶液预处理制备了AlO分子筛负载的Pt（Pt-AlO）催化剂。研究了预处理溶液在催化剂制备及Pt-AlO催化剂上甲醛（HCHO）分解过程中的作用。pH = 1的酸溶液对Pt在AlO表面的分散最为有利。Pt-AlO催化剂能够在室温下实现HCHO的完全稳定氧化。此外，通过N吸附研究确定，AlO分子筛的介孔结构、大比表面积和高吸附能力促进了其对HCHO的优异去除活性。原位漫反射红外傅里叶变换光谱（DRIFTS）研究确定二氧亚甲基（DOM）和甲酸盐物种为主要中间体。这些中间体随后在室温下被氧化为CO和H₂O。此外，还提出了HCHO去除的可能反应机理及表面羟基的再生途径。本研究为制备用于室内空气净化的实用低成本催化剂提供了新的见解。
