Yang Xuanyu, Cheng Xiaowei, Ma Junhao, Zou Yidong, Luo Wei, Deng Yonghui
Department of Chemistry, State Key Laboratory of Molecular Engineering of Polymers, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, iChEM, Fudan University, Shanghai, 200433, China.
State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai, 201620, China.
Small. 2019 Sep;15(39):e1903058. doi: 10.1002/smll.201903058. Epub 2019 Aug 7.
Active and stable catalysts are highly desired for converting harmful substances (e.g., CO, NO ) in exhaust gases of vehicles into safe gases at low exhaust temperatures. Here, a solvent evaporation-induced co-assembly process is employed to design ordered mesoporous Ce Zr O (0 ≤ x ≤ 1) solid solutions by using high-molecular-weight poly(ethylene oxide)-block-polystyrene as the template. The obtained mesoporous Ce Zr O possesses high surface area (60-100 m g ) and large pore size (12-15 nm), enabling its great capacity in stably immobilizing Pt nanoparticles (4.0 nm) without blocking pore channels. The obtained mesoporous Pt/Ce Zr O catalyst exhibits superior CO oxidation activity with a very low T value of 130 °C (temperature of 100% CO conversion) and excellent stability due to the rich lattice oxygen vacancies in the Ce Zr O framework. The simulated catalytic evaluations of CO oxidation combined with various characterizations reveal that the intrinsic high surface oxygen mobility and well-interconnected pore structure of the mesoporous Pt/Ce Zr O catalyst are responsible for the remarkable catalytic efficiency. Additionally, compared with mesoporous Pt/Ce Zr O -s with small pore size (3.8 nm), ordered mesoporous Pt/Ce Zr O not only facilitates the mass diffusion of reactants and products, but also provides abundant anchoring sites for Pt nanoparticles and numerous exposed catalytically active interfaces for efficient heterogeneous catalysis.
在低温尾气条件下，将车辆尾气中的有害物质（如一氧化碳、一氧化氮）转化为无害气体，急需高活性且稳定的催化剂。在此，我们采用溶剂蒸发诱导共组装法，以高分子量聚环氧乙烷-嵌段-聚苯乙烯为模板，设计制备了有序介孔CeZrO（0≤x≤1）固溶体。所制备的介孔CeZrO具有高比表面积（60-100 m²/g）和大孔径（12-15 nm），能够在不堵塞孔道的情况下稳定负载铂纳米颗粒（4.0 nm）。所制备的介孔Pt/CeZrO催化剂表现出优异的一氧化碳氧化活性，其100%一氧化碳转化率对应的温度（T100）低至130°C，并且由于CeZrO晶格中丰富的氧空位，具有出色的稳定性。结合各种表征手段对一氧化碳氧化进行的模拟催化评估表明，介孔Pt/CeZrO催化剂固有的高表面氧迁移率和良好连通的孔结构是其显著催化效率的原因。此外，与小孔径（3.8 nm）的介孔Pt/CeZrO-s相比，有序介孔Pt/CeZrO不仅有利于反应物和产物的质量扩散，还为铂纳米颗粒提供了丰富的锚定位点以及大量暴露的催化活性界面，以实现高效的多相催化。
