RE2Zr2O7+δ基烧绿石结构固体电解质及其中低温NOx传感性能研究

发展中低温NOx传感器是目前极具诱惑力和挑战性的课题，高效的中低温固体电解质的设计合成和作用机制是研究的焦点，而烧绿石结构固体电解质材料是一个新的探索方向。本项目基于前期探索研究，提出采用碱土和稀土金属离子对具有开放式结构的RE2Zr2O7+δ基固体电解质的A、B位进行掺杂来同时提高材料的离子电导率和NOx响应性的新思路，详细研究材料的优化合成和控制制备、晶体结构调变、NOx传感性能及其构效关系。以提高其中低温离子电导率和对NOx传感的灵敏度、稳定性为目标，表征材料的电导率随温度的变化特性，揭示RE2Zr2O7+δ基固体电解质对NOx传感的物理化学机制，搞清楚影响RE2Zr2O7+δ基固体电解质的结构与导电性能的关键因素，探索提高传感器对NOx敏感性和稳定性的新途径。该研究对新型高效NOx传感材料的设计制备有十分重要的科学意义，对燃油汽车节能减排和城市环境保护具有重要的实际应用价值。

The development of low, moderate-temperature NOx sensors is currently a challenging task. The focus was on the design and preparation of solid electrolyte effective at low and moderate temperature. The solid electrolyte with the pyrochlore structure is a new research direction. Based on the results obtained early, the proposal suggests a new idea to simultaneously improve the ionic conductivity and NOx responsiveness by codoping the A and B sites of RE2Zr2O7+δ based solid electrolytes with alkaline earth and rare earth metal ions, respectively. The controlled synthesis and optimization of such materials, the tuning of crystal structure, the NOx sensing performance, and the structure-performance relationship will be studied in detail. The proposal aims at the improvement of ionic conductivity at low and moderate temperature, and the sensitivity and stability of NOx sensor, studies the variation of conductivity VS temperature. The physical and chemical mechanisms of NOx sensing of RE2Zr2O7+δ based solid electrolytes will be clearly revealed. The essential factors affecting the structure and electrical properties of RE2Zr2O7+δ based solid electrolytes at low and moderate temperature are clarified. The new way to improve the sensitivity and stability of the RE2Zr2O7+δ based NOx sensor will be explored. The study is of important and scientific significance to design highly efficient NOx sensing materials. It has the important value for the practical application in energy saving, emission reduction of the fuel automobile, and environmental protection.