氧化铈（CeO2）具有优异的氧化还原性能，可以作为氮氧化物还原催化剂的载体、助剂和活性组分，但是目前对于氮氧化物在氧化铈表面吸附与反应微观机理的认识仍不完全清楚。本项目以理想配比、含氧空位和重构的氧化铈单晶表面为模型催化剂，以氧化铈纳米晶作为桥联单晶模型催化剂和实际工作粉体催化剂的另一类模型催化剂，利用超高真空红外光谱并结合第一性原理计算研究氮氧化物分子（NO、N2O和NO2）在氧化铈单晶和纳米晶表面的吸附态、吸附位置、吸附构型、结合能、振动频率和分子间相互作用，并采用微反技术考察氧化铈纳米晶催化还原氮氧化物的形貌/晶面效应。从二维的单晶到三维的纳米晶梯次构筑模型催化剂，将有助于在原子和分子层面理解催化剂的构效关系并揭示催化反应微观机理，为氮氧化物还原催化剂的理性设计制备提供指导。

Ceria (CeO2) has superior redox properties and has been used as support, promoter or active component of catalysts for abating nitrogen oxides (NOx). However, the adsorption and reaction mechanisms of NOx on ceria surfaces are still not fully understood. In this project, we will employ stoichiometric, reduced and reconstructed bulk ceria single crystals as model catalysts and ceria nanocrystals as a bridge between single crystal model catalysts and practical powder catalysts. Using ultra-high vacuum Fourier-transform infrared spectroscopy in conjunction with ab initio theoretical calculations, the adsorption states, adsorption sites, adsorption configurations, binding energy, vibration frequency, and molecular interaction of nitrogen oxides (NO2, NO and N2O) on ceria single crystals and nanocrystals will be studied. We also will use micro-scale reaction system to evaluate the catalytic performance of ceria nanocrystals in NOx reductions. Surface chemistry studies, ranging from single crystals to nanocrystals, are able to elucidate the structure-function relationships and catalytic reaction mechanism at the atomic and molecular levels, and will give guidance to the development of more efficient catalysts.