Université Lyon 1, CNRS, UMR 5615, Laboratoire des Multimatériaux et Interfaces, 43 boulevard du 11 Novembre 1918, F-69622 Villeurbanne, France.
Phys Chem Chem Phys. 2010 Nov 28;12(44):14651-65. doi: 10.1039/c0cp00295j. Epub 2010 Oct 13.
Cobalt-catalyzed hydrolysis of sodium borohydride (NaBH(4)) has attracted great attention since the hydride is believed to be promising hydrogen storage material. Cobalt is an efficient metal catalyst and has already proven to be a potential alternative to noble metals. Nevertheless it is not stable. Indeed it transforms into a Co- and B-based material when on contact with NaBH(4). Through ex situ characterizations (e.g. ICP, XRD, XPS and SEM), the Co- and B-based material has been supposed to be either a cobalt boride Co(x)B (with x from 1 to 3) or a Co-B alloy. This contradiction is the topic of the present paper. Herein, the literature dedicated to the Co-catalyzed NaBH(4) hydrolysis is exhaustively surveyed. The results of the ex situ characterizations are largely discussed, for example that: (i) the ex situ characterized Co(x)B or Co-B might be different from the in situ formed Co- and B-based catalyst; (ii) there is no clear evidence of the formation of either Co(x)B or Co-B; (iii) the in situ formed catalyst would change in accordance with a cycle in the course of the hydrolysis; and (iv) in situ characterizations are clearly required but their setting up is a challenge. These conclusions, among others, are argued.
钴催化硼氢化钠（NaBH(4)）的水解引起了广泛关注，因为人们认为该氢化物是一种有前途的储氢材料。钴是一种高效的金属催化剂，已经被证明是贵金属的潜在替代品。然而，它并不稳定。事实上，当它与 NaBH(4)接触时，它会转化为 Co 和 B 基材料。通过原位表征（例如 ICP、XRD、XPS 和 SEM），该 Co 和 B 基材料被认为是钴硼化物 Co(x)B（其中 x 从 1 到 3）或 Co-B 合金。这种矛盾是本文的主题。本文详尽地综述了关于钴催化 NaBH(4)水解的文献。大量讨论了原位和非原位表征的结果，例如：（i）非原位表征的 Co(x)B 或 Co-B 可能与原位形成的 Co 和 B 基催化剂不同；（ii）没有明确证据表明形成了 Co(x)B 或 Co-B；（iii）原位形成的催化剂会随着水解过程中的循环而发生变化；（iv）需要进行原位表征，但设置原位表征是一个挑战。这些结论，以及其他结论，都进行了论证。
