Pt/H-TiO2催化剂制备及其甲醇电催化氧化性能

以四氯化钛为前驱体，采用水热法合成二氧化钛纳米棒（TiO₂，白色），在纯H₂气氛，将其550 ^oC热处理2 h，即得有氧缺陷和Ti³⁺填隙原子的二氧化钛纳米棒（H-TiO₂，灰黑色）. 将Pt纳米粒子（~ 1.9 nm）负载于此两种二氧化钛纳米棒上，制得Pt/TiO₂和Pt/H-TiO₂催化剂. XRD和XPS测试表明，氢处理TiO₂晶型没有变化，仍属金红石型，但增加了Ti-OH表面物种. 电化学测试表明，H-TiO₂载体能够增强氧在Pt表面的吸脱附能力，从而提高其甲醇电催化氧化活性，Pt/H-TiO₂电极甲醇氧化峰电流密度为Pt/TiO₂电极的1.6倍、Pt/C电极的2.1倍.

Preparation of Pt/H-TiO2 Catalyst with Improved Catalytic Performance for Methanol Electrooxidation

White TiO₂ nanorods were synthesized by hydrothermal method with TiCl4 as a precursor. As-synthesized TiO₂ nanorods were further subjected to high-temperature (550 ^oC) heat treatment for 2 h under H2 atmosphere to prepare gray black hydrogen-treated TiO₂ (H-TiO₂) nanorods with oxygen vacancies and Ti³⁺ interstitial atoms. The Pt nanoparticles of 1.9 nm were supported on these two types of TiO₂ nanorods to form Pt/TiO2 and Pt/H-TiO₂ catalysts. XRD data indicates that the crystal structure of TiO₂ was still reserved as rutile after hydrogen treatment, but the surface was covered by some Ti-OH species, as evidenced by XPS test. Electrochemical tests demonstrate that the oxygen vacancies of H-TiO₂ can enhance the adsorption/desorption of oxygen on Pt nanoparticles, which promotes the electrocatalytic activity of H-TiO₂ towards methanol oxidation. As a result, the peak current density of methanol oxidation on Pt/H-TiO₂ was 1.6 and 2.1 times those of methanol oxidation on Pt/TiO₂ and Pt/C, respectively.