具有高分散活性位的新型铜铈体系催化剂的设计、制备及催化性能研究

Carbon monoxide in the hydrogen rich gases needs to be decreased to a trace-level because it can poison the Pt electrode in proton exchange membrane fuel cell (PEMFC). Among the current available methods to remove CO, preferential oxidation of CO (CO-PROX) was proved to be the most straightforward and economic one. Developing non-noble catalysts with high activity and anti-deactivation have been of vital importance in the commercial application of PEMFC. Of the catalysts used for CO-PROX, copper and cerium oxides catalysts have also shown promising properties. However, the CuO-CeO2 catalysts have a serious disadvantage that their activity will be deactivated with the sintering of active copper species. To overcome the weak point, metal-organic frameworks (MOF) were used for the preparation of Cu-Ce catalysts due to their high surface areas, various porous structures and highly exposed metal ions. The catalysts with high dispersed active sites can improve the CO conversion and O2 selectivity at low temperature. In this work, the activity and stability of catalysts will be tested. And the effects of preparing condition, methods of creating active sites will be investigated. Furthermore, a series of characterization techniques will be employed to the study of MOF using for gas catalytic reaction. It can provide a new idea for designing novel catalysts for CO oxidation and other catalytic oxidation reaction.

开发具有高活性、抗失活的非贵金属CO优先氧化反应催化剂，是降低质子交换膜燃料电池(PEMFC)商业应用成本的瓶颈问题之一。铜铈体系催化剂价格低性能好，但因活性铜物种在催化剂制备及反应过程中易团聚、烧结而存在稳定性差、易失活等问题。针对此，本项目拟利用金属有机框架化合物(MOF)具有高比表面积、孔道结构丰富可调及金属离子全暴露的优势，制备新型铜铈体系催化剂，获得高度分散的活性铜物种，提高低温条件下CO转化率及富氢条件下的选择性；通过性能测试及各项表征技术对催化剂的制备方法、条件及MOF材料上活性位的创立方法进行系统研究；初步探索催化机理。该项目可为CO优先氧化及其他催化氧化反应提供催化剂设计、制备的新思路。

铜铈金属氧化物催化剂是研究广泛的CO优先氧化催化剂，其价格低性能好，但制备及反应过程中活性铜物种易团聚而影响活性，本项目采用水热合成法制备了系列MOFs，以其为前驱体制备了系列具有高分散活性位的CuO-CeO2催化剂；并制备了系列纳米结构CuO/CeO2催化剂，测试了其对富氢条件下CO优先氧化反应的活性，并通过比较不同制备方法、调适铜铈比例、改变前驱体形貌、采用不同焙烧温度、Mn掺杂等调变催化剂结构，结合多种表征手段，对前驱体及催化剂物性结构、形貌特点、表面组成、氧化还原性、金属氧化物间的协同效应进行了深入研究，为开发和研究高效且低成本的CO优先氧化催化剂提供了理论依据和实验基础。