COx-free hydrogen production from ammonia - mimicking the activity of Ru catalysts with unsupported Co-Re alloys
COx-free hydrogen production from ammonia - mimicking the activity of Ru catalysts with unsupported Co-Re alloys
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DOI：
10.1016/j.apcatb.2020.119405
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发表时间：
2021-01-01
影响因子：
22.1
通讯作者：
Torrente-Murciano, Laura
中科院分区：
文献类型：
--
作者：
Kirste, Karsten G.;McAulay, Kate;Torrente-Murciano, Laura
氨按需制氢是一个挑战，限制了氨作为长期氢载体的实施，以克服与氢存储相关的困难。在此，我们介绍了通过结合具有高和低N-吸附原子吸附能的金属来开发用于氨按需制氢的催化剂。在这种情况下，Co-Re(Co-Re)催化剂表现出与Ru类似的高活性。EXAFS/XANES分析表明，双金属Co-Re的贡献对催化剂连续运行的活性和稳定性有影响，在氨气气氛下没有观察到氮化物(Co-N和Re-N)的形成。虽然钴在氨气中被部分重新氧化，但在Re存在下，在更高的温度下观察到再次还原，这与伴随着微小结构变化的催化活性一致。这些结果为开发高活性合金基氨分解催化剂提供了依据。
On-demand production of hydrogen from ammonia is a challenge limiting the implementation of ammonia as a long term hydrogen vector to overcome the difficulties associated with hydrogen storage. Herein, we present the development of catalysts for the on-demand production of hydrogen from ammonia by combining metals with high and low N-adatom adsorption energies. In this way, cobalt-rhenium (Co-Re) catalysts show high activity mimicking that of ruthenium. EXAFS/XANES analyses demonstrate that the bimetallic Co-Re contribution is responsible for the activity and the stability of the catalysts in consecutive runs with no observable formation of nitrides (Co-N and Re-N) occurring under the ammonia atmosphere. While cobalt is partially re-oxidised under ammonia, re-reduction in the presence of rhenium is observed at higher temperatures, coinciding with the on-set of catalytic activity which is accompanied by minor structural changes. These results provide insight for the development of highly active alloy based ammonia decomposition catalysts.