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运用超高真空程序升温反应(TPRS)技术研究了氧在电解银上的化学吸附。在宽广的压力范围内(1—10~(-8)torr)考察了几种吸附氧种的变化规律,并观察到在覆盖度为0.2—0.6时表面吸附物种的突变。用同位素交换和CO滴定实验证实了在电解银表面存在三种氧吸附态:(1) 弱的未解离的分子态吸附(E_d=92KJ/mol,v=4×10~(11_S-1));(2) 强的解离的原子态吸附(E_d=134kJ/mol,v=4.7×10~(13_S-1));(3)氧在银体相中扩散。进一步的实验发现,分子态吸附氧与表面杂质的存在有关。用等温脱附技术研究了氧在银中的扩散,得到了扩散量随温度增加的定性规律。
The chemisorption of oxygen on silver electrode was studied by ultra high temperature programmed thermal reaction (TPRS). In a wide range of pressure (1-10 ~ (-8) torr) investigated the variation of several species of adsorbed oxygen species, and observed changes in the surface adsorption species with a coverage of 0.2-0.6. It was confirmed by isotope exchange and CO titration experiments that there are three oxygen adsorption states on the surface of silver: (1) weak non-dissociated molecular adsorption (E_d = 92KJ / mol, v = 4 × 10-11_S-1) ); (2) strong dissociative atomic adsorption (E_d = 134kJ / mol, v = 4.7 × 10 ~ (13_S-1)); and (3) diffusion of oxygen in the silver phase. Further experiments found that molecular oxygen adsorption and the presence of surface impurities. The isothermal desorption technique was used to study the diffusion of oxygen in silver, and the qualitative law of diffusion with temperature was obtained.