以单分散金属纳米粒子和形貌可控的氧化物为结构单元构筑新型金属-氧化物催化剂

纳米尺度上的催化剂微观结构如尺寸、形貌、界面等是决定催化性能的关键因素。常规的负载型金属催化剂普遍存在粒径尺寸分布宽、金属?氧化物表面和界面结构的不规整等问题。这不仅降低了活性组分的利用效率，而且严重制约了对催化剂活性位的认知。本项目针对多相催化中广泛应用的TiO2、ZrO2等负载的Pd、Cu、Co等金属催化剂，利用纳米催化中的尺寸效应、形貌效应和界面效应并结合材料化学的最新进展，以单分散金属纳米粒子和形貌各异的氧化物为结构基元，构筑枝型、火柴杆型、落位优先型等新结构的金属?氧化物纳米材料。这其中的关键科学问题是理解金属粒子与氧化物晶面的相互作用机制并调控其在氧化物表面上的选择落位。将这类金属?氧化物催化剂用于重要的加氢或氧化反应，结合现化表征技术深入研究催化剂的表面、界面结构及空间分布，以强化对催化剂活性位和金属-载体作用机制的理解，为催化剂的设计与制备提供必要的理论指导和实践基础。

The microstructure of catalysts at the nano-scale, such as size, morphology, interface is the key issue in heterogenous catalysis to achieve the desired performance. The conventional metal supported catalysts usually present wider size distribution and the un-uniform superficial and interfacial structure, which not only lowers the efficiency of active metals, but also weakens the structure-performance relationship and the active sites. The rapid advancement in materials science has now offered greater feasibility to tailor the size and shape of solid catalyst nanoparticles using the bottom-up approach in liquid solution. By virtue of the size-dependent effect, the morphology-dependent effect and interfacial effect in the nanocatalysis, this project was proposed to construct novel metal-oxides hybrid nanostructures in the shape of branched, matchstick- like and site-preferential applying the monodispersed Pd, Cu, Co etc. metal colloids and morphology-controlled TiO2、ZrO2 etc. oxides as the building blocks. The essential parameter is to control the spatial distribution of metal nanoparticles on the exposed crystal facets of oxide supports through the optimization of mutual interaction. Employing morphology-tunable metal oxides as support to load metal nanoparticles, not only favors the fabrication of more efficient nanocatalysts for hydrogenation or oxidation reactions, but also helps to improve the uniformity of microstructure and to elucidate the active sites and the intrinsic mechanism of strong metal-support interaction, which is one of the fundamental issues in heterogenous catalysis.