Abstract:
Room-temperature catalytic oxidation of formaldehyde (HCHO) has been extensively investigated due to its high efficiency, convenience, and environmental friendliness. Herein, nickel-iron layered double hydroxide (NiFe LDH) nanosheets were synthesized in-situ on a nickel foil (NF) using a facile one-step hydrothermal method, followed by the deposition of ultra-low content (0.069 wt%) of Pt nanoparticles through NaBH4 reduction. The resulting three-dimensional (3D) hierarchical Pt/NiFe-NF catalyst exhibited exceptional activity for the complete decomposition of formaldehyde to carbon dioxide (CO2) at room temperature (∼95 % conversion within 1 h), as well as remarkable cycling stability. The 3D porous structure of Pt/NiFe-NF provides fast transport channels for the diffusion of gas molecules, making the active catalyst surfaces more accessible. Moreover, abundant hydroxyl groups in NiFe LDH serve as adsorption centers for HCHO molecules to form dioxymethylene (DOM) and formate intermediates. Furthermore, electronic interactions between NiFe LDH and Pt enhance the adsorption and activation of O2 on Pt surfaces, leading to the complete decomposition of intermediates into non-toxic products. This work presents new insights into the design and preparation of Pt-based 3D hierarchical catalysts with surface-rich hydroxyl groups for the efficient removal of indoor HCHO.
摘要:
甲醛的室温催化氧化(HCHO)因其高效,便利性,和环境友好。在这里,镍-铁层状双氢氧化物(NiFeLDH)纳米片在镍箔(NF)上使用简单的一步水热法原位合成,然后通过NaBH4还原沉积超低含量(0.069wt%)的Pt纳米颗粒。所得的三维(3D)分层Pt/NiFe-NF催化剂在室温下表现出甲醛完全分解为二氧化碳(CO2)的特殊活性(在1小时内转化率约95%),以及显着的循环稳定性。Pt/NiFe-NF的3D多孔结构为气体分子的扩散提供了快速的传输通道,使活性催化剂表面更容易接近。此外,NiFeLDH中丰富的羟基用作HCHO分子的吸附中心,以形成二甲醛(DOM)和甲酸酯中间体。此外,NiFeLDH与Pt之间的电子相互作用增强了O2在Pt表面的吸附和活化,导致中间体完全分解为无毒产品。这项工作为设计和制备具有表面富含羟基的Pt基3D分层催化剂提供了新的见解,可有效去除室内HCHO。