气相团簇法探究铑-稀土氧化物催化剂对汽车尾气中有害气体小分子的作用机理

Rare-earth based three-way catalysts (TWCs) have attracted significant interest and become the focus of researchers in recent years in order to reduce or even replace the noble metals contained in TWCs which are mainly used for automobile exhaust purification; at the same time, it is of great importance to understand the interaction mechanism between those catalysts and small molecules in the harmful automobile exhaust, which can assist researchers to design more efficient TWCs with high activity, high heat-stability, high selectivity and controllability. With Rh - rare earth oxide clusters as the studied model, this project intends to employ the art of gas phase clusters by combining the experimental tools such as laser ablation, ion-trap reactor, time-of-flight mass spectroscopy and theoretical methods such as density functional theory to study the adsorption, activation and conversion of small molecules including CO, HC and NOx on the target clusters. By investigating the electrical structures and active sites of the clusters with different size and composition, the mutual interaction between supported part Rh and the rare earth oxide support will be explored on the molecular level, which can help us to comprehend the influence of the cluster structure on the reaction activity. These studies will provide scientific basis to design rare-earth based catalysts.

为减少甚至取代用于汽车尾气净化的三效催化剂TWCs（Three-Way Catalysts）中贵金属的使用，基于稀土元素的TWCs成为研究者重点关注和研发对象；同时，认清催化剂对汽车尾气中有害气体小分子的作用机理对设计高活性、高热稳定性、高选择性、可调控的TWCs具有重要意义。本项目拟采用气相团簇法，以铑-稀土形成的异核氧化物团簇为模型，利用量子理论方法预测出具有活性的团簇，采用激光溅射、离子阱反应器、飞行时间质谱等实验手段测量CO、HC及NOx在团簇上的吸附、活化和转换，并与理论预测相互验证，从分子层次上探究催化剂的被担载部分(Rh)与担载部分(稀土氧化物)之间的相互作用，不同尺寸及比例的Rh-稀土氧化物团簇的电子结构及活性位点，得到团簇结构、组成与其反应活性的依赖关系，为理性设计稀土催化剂提供科学依据。

为减少甚至取代用于汽车尾气净化的三效催化剂TWCs（Three-Way Catalysts）中贵金属的使用，基于过渡金属元素的TWCs成为研究者重点关注和研发对象；同时，认清催化剂对汽车尾气中有害气体小分子的作用机理对设计高活性、高热稳定性、高选择性、可调控的TWCs具有重要意义。本项目拟采用气相团簇法，以贵金属-过渡金属形成的异核氧化物团簇为模型，利用量子理论方法预测出具有活性的团簇，采用激光溅射、离子阱反应器、飞行时间质谱等实验手段测量CO、HH及NOx在团簇上的吸附、活化和转换，并与理论预测相互验证，从分子层次上探究催化剂的被担载部分(贵金属)与担载部分(异核过渡金属氧化物)之间的相互作用，不同尺寸及比例的贵金属-过渡金属氧化物团簇的电子结构及活性位点，得到团簇结构、组成与其反应活性的依赖关系，为理性设计汽车尾气催化剂提供科学依据。