A series of titania nanowires containing different Na content (Na_xTiO₂) were prepared from sodium titanate by varying the pH value of ion-exchange. They were used to load the Pt nanoparticles for low temperature formaldehyde catalytic oxidation. As prepared samples were systematically characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS), in situ diffuse-reflectance infrared Fourier transform spectroscopy (DRIFTS), temperature programmed reduction/desorption/oxidation (TPR/TPD/TPO) and so on. The results showed that Na_xTiO₂ were consisted of anatase and sodium titanate. As pH value increased, the surface area and anatase content of catalyst decreased. Pt particles on Na_xTiO₂ were more easily oxidized and had smaller size but less exposed atoms compared with those on pure TiO₂. The HCHO catalytic oxidation result exhibited that Pt/Na_xTiO₂ catalysts possessed excellent HCHO catalytic oxidation at ambient temperature that were 8.9–52.8 times the activities as that of Pt/TiO₂. Kinetic studies manifested the easy activation of HCHO reaction over Pt/Na_xTiO₂ catalysts. Structure-performance analysis showed that the enhanced performance of Pt/Na_xTiO₂ catalysts was mainly attributed to two factors: increase in HCHO adsorption amount and change in HCHO decomposition pathway. According to HCHO-DRIFTS, linearly adsorbed CO generated from formate can react with hydroxyls to be carbonate/bicarbonate over Pt/Na_xTiO₂ catalysts. Simultaneously, the formate in Pt/Na_xTiO₂ catalyst with high Na content was also decomposed into a weak adsorbed CO. Both reaction pathways avoided the strong adsorption of CO on Pt/Na_xTiO₂ catalysts, which can facilitate the HCHO decomposition.

通过改变离子交换的pH值，由钛酸钠制备了一系列含有不同Na含量的二氧化钛纳米线（Na _x TiO ₂）。它们被用于负载Pt纳米颗粒，用于低温甲醛催化氧化。通过X射线衍射（XRD），透射电子显微镜（TEM），X射线光电子能谱（XPS），原位漫反射红外傅里叶变换光谱（DRIFTS），程序升温还原/解吸/氧化（TPR / TPD / TPO）等。结果表明，Na _x TiO ₂由锐钛矿和钛酸钠组成。随着pH值的增加，催化剂的表面积和锐钛矿含量降低。与纯TiO ₂相比，Na _x TiO ₂上的Pt颗粒更容易被氧化，尺寸更小，但暴露的原子更少。HCHO催化氧化结果表明，Pt / Na _x TiO ₂催化剂在环境温度下具有优异的HCHO催化氧化能力，是Pt / TiO ₂活性的8.9-52.8倍。动力学研究表明，在Pt / Na _x TiO ₂催化剂上HCHO反应易于活化。结构性能分析表明，Pt / Na的性能增强_x TiO ₂催化剂主要归因于两个因素：HCHO吸附量的增加和HCHO分解途径的改变。根据HCHO-DRIFTS，在Pt / Na _x TiO ₂催化剂上，由甲酸盐生成的线性吸附的CO可以与羟基反应生成碳酸盐/碳酸氢盐。同时，高Na含量的Pt / Na _x TiO ₂催化剂中的甲酸酯也被分解为弱吸附的CO。两种反应路径均避免了CO在Pt / Na _x TiO ₂催化剂上的强吸附，从而促进了HCHO的分解。