The OH--driven synthesis of Pt-Ni nanocatalysts with atomic segregation for alkaline hydrogen evolution reaction
The OH--driven synthesis of Pt-Ni nanocatalysts with atomic segregation for alkaline hydrogen evolution reaction
复制标题
用于碱性析氢反应的原子偏聚 Pt-Ni 纳米催化剂的 OH 驱动合成
DOI：
10.1039/c8ta12250d
复制
发表时间：
2019
影响因子：
11.9
通讯作者：
Liang Xin
中科院分区：
文献类型：
--
作者：
Zhang Cong;Chen Biaohua;Mei Donghai;Liang Xin
为了寻找有效的碱性析氢反应催化剂，人们进行了大量的研究。尤其是具有异质结构的铂基材料表现出了优异的电催化性能。然而，关于合金向异质结构的转变以及活性优异的主要原因的研究还很少。在此，我们证明了在合成铂镍合金时，只需引入氢氧化钠就可以形成铂镍异质结构。密度泛函理论计算表明，添加的OH-−可以影响原子还原和迁移的势垒，从而推动形成具有原子偏析的异质结构。此外，还证明了HER性能的提高归功于原子偏析产生的有利的H和OH能级。酸处理强调了决定酶活性的关键因素。本工作证明，添加OH-−可以形成具有原子偏析的纳米催化剂，调节铂-镍催化剂的原子偏析是优化其对H和OH的吸附能力，从而提高碱性HER性能的有效途径。
Intense researches for pursuing effective catalysts for alkaline hydrogen evolution reaction (HER) have been carried out. Particularly, Pt-based materials having heterostructures have shown excellent electrocatalytic performance. However, there are only few investigations on the transformation from an alloy to a heterostructure and the main reason for superior activity. Herein, we demonstrated that Pt–Ni heterostructures could be formed by only introducing NaOH in the synthesis of Pt–Ni alloys. Density functional theory calculations revealed that the added OH− can influence the energy barriers of atomic reduction and migration, thus driving the formation of a heterostructure with atomic segregation. Moreover, it was proved that the enhanced HER performance is attributed to favorable H and OH energetics arising from the atomic segregation. Acid treatment emphasized the key factors in determining the activity. This work proves that adding OH− can lead to the formation of nanocatalysts with atomic segregation, and tuning the atomic segregation of Pt–Ni catalysts is an effective way to optimize their H and OH adsorption abilities, thus enhancing the alkaline HER performance.