高温水蒸气毒化对钯膜表面状态与渗氘能力的影响

采用H2O(g)在300℃与900℃之间对Pd膜表面进行了毒化,将毒化后的Pd膜在常温下与氢气进行反应,并在500℃进行了氘气渗透试验。采用XPS、SEM等对反应前后Pd膜表面状态进行了表征与分析,研究了H2O(g)的毒化作用与吸氢反应对Pd膜表面形貌与化学成分的影响与机理。实验表明:当毒化温度低于500℃时,H2O(g)对Pd膜表面无明显影响;当毒化温度高于500℃,H2O(g)会导致Pd膜表面出现微孔,且随着毒化温度升高,微孔数量与体积逐渐增加;当温度达到600℃以上时,H2O(g)毒化会造成Pd膜表面出现细微裂纹。H2O(g)与Pd膜在300℃与900℃之间不但不会产生化学变化,其表面原有的吸附杂质反而得到了明显的去除,且在600℃以上反应后钯膜的透氘性能也得到了提高。

Effect of Water Vapour Poison on the Surface Condition and Deuterium Permeability of Palladium Membrane

The poison of palladium membrane in H2O (gas) and the hydrogenization of the poisoned membrane were proceeded in a silica tubular furnace. The hydrogen isotope permeation capacity of palladium membrane was tested. The variation of palladium membrane phase was analyzed by XPS and SEM. The causes and the mechanism of the variation were discussed. The results show that the content of adsorptive C and O on the palladium surface can be decreased by the reaction between H2O (gas) and palladium surface without variation of chemical state. Some cracks can be observed on the palladium surface at a higher reaction temperature, which account for a physical change. At room temperature, there are no obvious changes on the palladium surface after the palladium membrane deoxidized again by H2. The deuterium permeability of Pd membrane which has reacted with H2O (gas) is higher than the original membrane. The improvement of deuterium permeability could be ascribed to the improving surface cleanness caused by the reaction between H2O (gas) and palladium surface.