高分散Pd-Pt/TiO2/Ti双金属消氢催化剂的制备及其耐高温性能研究

As the important security equipment installed within containments of nuclear reactors in order to remove hydrogen and convert it to steam, the passive autocatalytic recombiner (PAR) has wide application prospects. The elimination hydrogen catalyst is the key component of the PAR. However, the high temperature resistance of the elimination hydrogen catalyst is unsatisfactory, which has attracted significant attention as an scientific problem at present. Thus this project aims at to solve the problem by in-situ fabricating TiO2 on support Ti, in order to prevent the phase diffusion between noble metal active component and support Ti. Meanwhile, TiO2 on the surface of Ti could suppress the hydrogen embrittlement of Ti. Furthermore, this project is going to take advantage of the MOCVD technique, which has the characteristics of moderate reaction temperature and good uniformity of the deposited particles, to synthesize Pd-Pt bimetallic catalyst supported on TiO2/Ti. And then the systematic investigation of the hydrogen elimination performance of the Pd-Pt bimetallic catalysts is going to be carried out. The close relationship between the TiO2/Ti support structure, composition of noble metal, particle size and the elimination hydrogen properties will be explored in detail. In order to obtain an effective means of improving the high temperature stability of the catalysts, the synergistic effect of the two different metals will be studied. And the mechanism of the high temperature resistant performance for the catalysts will be revealed. This project will provide essential knowledge foundation to develop elimination hydrogen catalysts with high performance.

非能动氢复合器作为核电厂安全壳内重要的安全设备，有着广泛的应用前景，但是其核心部件消氢催化剂在高温下热稳定性不足的缺点仍然是目前需要重点关注的科学问题。为此，本项目提出在金属Ti基载体表面原位制备TiO2过渡层的思想，一方面可以抑制贵金属活性组分与金属载体之间的相扩散，另一方面也可以抑制Ti基载体发生氢脆现象。同时，利用MOCVD法相对较温和的反应温度以及粒子沉积均匀性好等优点，合成粒径、组成可控的Pd-Pt/TiO2/Ti双金属消氢催化剂，系统考察该系列催化剂的消氢反应性能。通过研究TiO2/Ti载体结构、贵金属组成、颗粒粒度与消氢性能之间的关系，揭示双金属催化剂中不同金属间的协同作用机制，阐明该系列催化剂在改善其耐高温性能方面的作用，获得提高催化剂高温稳定性的有效手段，为开发高性能消氢催化剂提供必要的知识基础。

非能动氢复合器作为核电厂安全壳内重要的安全设备，有着广泛的应用前景，但是其核心部件消氢催化剂在高温下热稳定性不足的缺点仍然是目前需要重点关注的科学问题。本项目通过MOCVD法制备得到了消氢性能优异，耐高温性能良好的Pd-Pt/TiO2/Ti催化剂。结果表明Ti基载体的改性采用煅烧法相比水热法更简单，载体稳定性更好。煅烧法引入TiO2负载贵金属Pd-Pt与Ti基未改性载体负载贵金属Pd-Pt所得催化剂相比，其消氢性能和耐高温性能更为优异，进一步说明了TiO2过渡层在改善其耐高温性能方面的作用。研究结果为开发高性能消氢催化剂提供必要的知识基础。