In situ generation of hydrogen from water by aluminum corrosion in solutions of sodium aluminate
In situ generation of hydrogen from water by aluminum corrosion in solutions of sodium aluminate
复制标题
DOI：
10.1016/j.jpowsour.2008.11.009
复制
发表时间：
2009-07
影响因子：
9.2
通讯作者：
L. Soler;A. M. Candela;J. Macanás;M. Muñoz;J. Casado
中科院分区：
文献类型：
--
作者：
L. Soler;A. M. Candela;J. Macanás;M. Muñoz;J. Casado
描述了一种利用铝酸钠溶液中的铝从水中获取氢气的新工艺，并与氢氧化钠水溶液中获得的结果进行了比较。该过程仅消耗水和铝，这两种原材料比用于原位制氢的其他化合物（例如碳氢化合物和化学氢化物）便宜得多。因此，我们的工艺可能是一种经济可行的替代氢来供应燃料电池的方法。结果表明，当在水溶液中使用 NaAlO2 代替 NaOH 时，氢气生产的最大速率和产率有所提高。使用高于 0.65M 的 NaAlO2 浓度已达到 100% 的产率，并且已证实浓度低于 0.75M 时的一级动力学。验证了 NaAlO2 水溶液的两种不同的非均相动力学模型。 NaAlO2 过程的活化能 (Ea) 为 71kJmol−1，证实了化学步骤的控制。提出了统一 NaOH 和 NaAlO2 溶液中 Al 腐蚀行为的机制。该工艺的应用可以降低基于燃料电池的电源成本，目前燃料电池使用氢化物作为氢气生产的原材料。
A new process to obtain hydrogen from water using aluminum in sodium aluminate solutions is described and compared with results obtained in aqueous sodium hydroxide. This process consumes only water and aluminum, which are raw materials much cheaper than other compounds used for in situ hydrogen generation, such as hydrocarbons and chemical hydrides, respectively. As a consequence, our process could be an economically feasible alternative for hydrogen to supply fuel cells. Results showed an improvement of the maximum rates and yields of hydrogen production when NaAlO2was used instead of NaOH in aqueous solutions. Yields of 100% have been reached using NaAlO2concentrations higher than 0.65M and first order kinetics at concentrations below 0.75M has been confirmed. Two different heterogeneous kinetic models are verified for NaAlO2aqueous solutions. The activation energy (Ea) of the process with NaAlO2is 71kJmol−1, confirming a control by a chemical step. A mechanism unifying the behavior of Al corrosion in NaOH and NaAlO2solutions is presented. The application of this process could reduce costs in power sources based on fuel cells that nowadays use hydrides as raw material for hydrogen production.