三种疏水催化剂耐氚辐照稳定性初步研究

为考察3种疏水催化剂Pt-SDB(SDB为苯乙烯-二乙烯苯共聚物)，Pt-PTFE（PTFE为聚四氟乙烯），Pt-C-PTFE 的耐氚辐照稳定性，将其置于1.26×10¹²Bq/L的氚水中静态辐照210 d后，对其催化交换性能及催化剂中残存氚进行分析。结果表明，3种催化剂在氚的β辐照下未发生裂解，催化剂中氚的残存量随催化剂比表面积的增加而增加，基本没有发生结构上的氚取代反应；但在氚水辐照后，3种疏水催化剂的交换性能出现了不同程度的变化，按单位质量Pt粒子计算，在测试不确定度范围内Pt-PTFE和Pt-C-PTFE的转化率没有发生明显变化，Pt-SDB(1)的转化率下降了11.2％，Pt-SDB(2)的转化率下降了16.9％。

Preliminary Study on Irradiation Stability of Three Hydrophobic Catalysts

The irradiation stability of Pt-SDB(SDB, styrene-divinylbenzene copolymer)， Pt-PTFE(PTFE, polytetrafluoroethylene)， Pt-C-PTFE were preliminary investigated. These catalysts were immersed in tritiated water(HTO) whose ³H concentration is 1.26×10¹²Bq/Lfor 210 d. The chemical composition of the gaseous phase over the catalyst HTO system is analyzed by GC-MS. The residual tritium in the catalyst after 210 d immersion is measured. The catalytic activity of these catalysts towards ³H isotope exchange reaction before and after immersion in HTO is evaluated by determination of the conversion ratio of ³H. The experimental results show that no noble irradiation decomposition is observed for all these three catalysts. The residual amount of ³H in the catalysts after the experiment is found to increaseas their specific surface area increases, but the substitution of ³H for H or F is negligibly small. However, variation does occur to different extent. No appreciable variation in conversion ratio is detected in the cases of Pt-PTFE and Pt-C-PTFE,while a decrease of 11.2%and 16.9% is observed in the case of Pt-SDB(1) and Pt-SDB(2), respectively.