氧化物表面氧缺陷和表面羟基在多相催化体系中作用的模型体系研究

项目名称： 氧化物表面氧缺陷和表面羟基在多相催化体系中作用的模型体系研究

项目编号： No.20803072

项目类型： 青年科学基金项目

立项/批准年度： 2009

项目学科： 电工技术

项目作者： 姜志全

作者单位： 中国科学技术大学

项目金额： 19万元

中文摘要： 应用离子溅射结合真空环境下高温退火的方法，并利用气相原子氢与氧化物表面的相互作用，能够在氧化物表面上重复可控地制备出不同浓度的氧缺陷和表面羟基。研究了氧缺陷对负载金属纳米粒子性质的调控作用，给出了氧缺陷向纳米粒子转移电荷的直接的实验证据，并发现氧缺陷位在金属纳米粒子稳定性方面的显著作用。研究了CO与表面羟基的相互作用，第一次提供了直接的实验证据来阐述金属/氧化物界面处CO氧化的反应路径，在分子水平上加深理解Pt/氧化物纳米催化剂上低温水汽变换反应和CO选择氧化反应的反应机理。研究了氧化物表面羟基的反应性能随氧缺陷浓度的变化关系，发现表面羟基的反应性能受到氧缺陷浓度的调节和控制。此外，还开展了金属单晶表面上吸附质分解和反应的研究工作。上述研究结果共发表学术论文8篇，全部为SCI收录，包括Journal of the American Chemical Society (1篇)、Journal of Physical Chemistry C (2篇)、Journal of Molecular Catalysis A (1篇)。

中文关键词： 模型氧化物表面；氧缺陷；表面羟基；金属纳米粒子

英文摘要： By employing ion sputtering coupled with high-temperature annealing under UHV conditions, and the interplay between gas atomic hydrogen and oxide surfaces, oxygen vacancies and surfaces hydroxyl with various concentrations can be fabricated on the oxide surfaces reproducibly and controllably. On investigation of the tuning effect of oxygen vacancy on the property of supported metallic nanoparticles, we gave a direct experimental result for charge transfer from oxygen vacancy to metallic nanoparticles, and found a remarkable effect of oxygen vacancy on the stability of metallic nanoparticles. On investigation of the interaction between CO and surface hydroxyl, for the first time we provided direct experimental evidence to elucidate the reaction pathway for CO oxidation at metal/oxide interface, and then deep insights into the reaction mechanism and active site of the important low-temperature WGS (water-gas shift) and PROX (preferential oxidation of CO in excess H2) reactions catalyzed by Pt/oxide nanocatalysts at the molecular level. On investigation of the dependence of the surface hydroxyl reactivity on the concentration of oxygen vacancy, we found that the surface hydroxyl reactivity is regulated and controlled by the concentration of oxygen vacancy on oxide surfaces. We also investigated the decomposition and reaction of adsorbates on metallic single-crystal surfaces. We have published 8 academic papers, which are all indexed by SCI, including Journal of the American Chemical Society (1), Journal of Physical Chemistry C (2), Journal of Molecular Catalysis A (1).

英文关键词： Model oxide surface; Oxygen vacancy; Surface hydroxyl; Metal nanoparticles