The sorption of hydrogen isotopes by a composite nanostructured carbon material containing palladium clusters with an average size of 3–5 nm was studied in the temperature range of 8–290 K. The total amount of sorbed hydrogen strongly depends on the method of manufacturing the composite and is 2–4.5% of the sample mass. In the kinetics of hydrogen sorption and desorption by a composite, two processes with characteristic times differing by more than an order of magnitude are identified. The relatively fast process seems to be related to the filling of the cavities of the carbon matrix with hydrogen molecules, the longer one corresponded to the diffusion of hydrogen into the crystal lattice of palladium nanoclusters. Two temperature regions are found for the temperature dependences of the diffusion coefficients of hydrogen and deuterium in composite samples. Above 60 K, the diffusion activation energies in the sample containing palladium nanoclusters were more than twice the values obtained for the pure carbon matrix. Below 60 K, the diffusion coefficients of deuterium in the pure carbon matrix weakly depended on temperature. In the case of diffusion of hydrogen and deuterium into palladium nanoclusters, a change in the character of the temperature dependence was observed at a lower temperature ( ∼ 30 K). Below this temperature the activation energy decreased by approximately an order of magnitude.

中文翻译：

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含钯纳米团簇的多孔碳材料低温吸氢

在 8-290 K 的温度范围内研究了含有平均尺寸为 3-5 nm 的钯簇的复合纳米结构碳材料对氢同位素的吸附。 吸附氢的总量在很大程度上取决于制造复合材料的方法并且是样品质量的 2-4.5%。在复合材料的氢吸附和解吸动力学中，确定了特征时间相差超过一个数量级的两个过程。相对较快的过程似乎与用氢分子填充碳基体的空腔有关，较长的过程对应于氢扩散到钯纳米簇的晶格中。对于复合样品中氢和氘的扩散系数的温度依赖性，发现了两个温度区域。在 60 K 以上，包含钯纳米团簇的样品中的扩散活化能是纯碳基质获得的值的两倍多。低于 60 K，氘在纯碳基体中的扩散系数对温度的依赖性较弱。在氢和氘扩散到钯纳米团簇中的情况下，在较低温度（~30 K）下观察到温度依赖性特征的变化。低于此温度，活化能降低了大约一个数量级。含有钯纳米团簇的样品中的扩散活化能是纯碳基体所得值的两倍多。低于 60 K，氘在纯碳基体中的扩散系数对温度的依赖性较弱。在氢和氘扩散到钯纳米团簇中的情况下，在较低温度（~30 K）下观察到温度依赖性特征的变化。低于此温度，活化能降低了大约一个数量级。含有钯纳米团簇的样品中的扩散活化能是纯碳基体所得值的两倍多。低于 60 K，氘在纯碳基体中的扩散系数对温度的依赖性较弱。在氢和氘扩散到钯纳米团簇中的情况下，在较低温度（~30 K）下观察到温度依赖性特征的变化。低于此温度，活化能降低了大约一个数量级。