Palladium (Pd)-based membranes have been studied for many years, regarding applications in production and purifi-cation of hydrogen. The reaction of water gas shift (CO+ H2O ↔ CO2 + H2), for example, can advantageously be conducted in a Pd-based membrane reactor, where hydrogen produced selectively permeates the membrane [1]. When hydrogen permeates with an infinite selectivity, its passage is governed by sorption-diffusion mechanism through the atomic struc-ture. Among all metals, palladium is the material that exhibits the highest atomic hydrogen permeability, resulting from the high capability in the catalytic dissociation of H2 molecules it in its metallic structure [2]. However, the use of pure palladi-um membranes has some limitations [3]. When palladium alloys such as Pd-Ag are used, the result is a homogeneous solid solution with a fcc structure [4,5]. This alloy prevents the formation of hybrid phases, allowing higher hydrogen permeation along with chemical and mechanical stability, reducing also the overall cost of raw material [2].
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机译：基于钯（Pd）的膜已经研究了很多年，涉及到氢的生产和纯化中的应用。例如，水煤气变换反应（CO + H2O = CO2 + H2）可以在基于Pd的膜反应器中进行，该反应器中产生的氢气选择性地渗透到膜中[1]。当氢以无限的选择性渗透时，氢的通过受原子结构的吸附-扩散机制控制。在所有金属中，钯是具有最高原子氢渗透性的材料，这归因于H2分子在其金属结构中的催化分解能力高[2]。但是，使用纯钯膜有一些局限性[3]。当使用钯合金如Pd-Ag时，结果是具有fcc结构的均匀固溶体[4,5]。这种合金可防止杂化相的形成，从而允许较高的氢渗透以及化学和机械稳定性，还降低了原材料的总体成本[2]。
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