The isotope effect H → D on diffusion in proton-exchange membrane Nafion 212 is investigated using 1 H and 2 H nuclear magnetic resonance (NMR) diffusometry in a static magnetic field gradient in the temperature range from 200 to 332 K for proton and from 245 to 332 K for deuteron transport. The diffusion coefficients of both isotopes have identical temperature dependence, while proton diffusion is 1.4 times faster than deuteron diffusion at the same humidity. This difference indicates a significant influence of the mass of the diffusing particle and allows us to conclude that the Grotthuss mechanism or relay diffusion of H + or D + ions prevails over the vehicular mechanism involving H 2 O molecules or H 3 O + ions.

中文翻译：

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核磁共振扩散法研究同位素对 Nafion 扩散的影响

同位素效应 H → D 对质子交换膜 Nafion 212 中的扩散使用 1 H 和 2 H 核磁共振 (NMR) 扩散法在静磁场梯度中进行研究，温度范围为 200 至 332 K 质子和 245至 332 K 用于氘传输。两种同位素的扩散系数具有相同的温度依赖性，而在相同湿度下，质子扩散比氘核扩散快 1.4 倍。这种差异表明扩散粒子的质量有显着影响，并使我们能够得出结论，H + 或 D + 离子的 Grotthuss 机制或中继扩散优于涉及 H 2 O 分子或 H 3 O + 离子的车辆机制。