Efficient and Robust Hydrogen Evolution: Phosphorus Nitride Imide Nanotubes as Supports for Anchoring Single Ruthenium Sites
Efficient and Robust Hydrogen Evolution: Phosphorus Nitride Imide Nanotubes as Supports for Anchoring Single Ruthenium Sites
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DOI：
10.1002/ange.201804854
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发表时间：
2018-07
影响因子：
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通讯作者：
Jian Yang;Bingxu Chen;Xiaokang Liu;Wei Liu;Zhijun Li;Juncai Dong;Wenxing Chen;Wensheng Yan
中科院分区：
文献类型：
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作者：
Jian Yang;Bingxu Chen;Xiaokang Liu;Wei Liu;Zhijun Li;Juncai Dong;Wenxing Chen;Wensheng Yan
无定形氮化磷酰亚胺纳米管（HPN）被报道为稳定含有单金属位点的材料的新型基底。大量的悬空不饱和P空位起稳定作用。钌单原子（SA）的成功锚定之间的强配位相互作用的d轨道的Ru和孤对电子的N位于HPN矩阵。Ru原子的原子分散性可以通过X射线吸收精细结构测量和球差校正电子显微镜来区分。重要的是，Ru SAs@PN是一种用于0.5mH2SO4中析氢反应（HER）的优异电催化剂，在10 mA cm− 2时提供24 mV的低过电位和38 mV dec−1的塔菲尔斜率。 该催化剂在162 mA cm-2的大电流密度下的恒定电流测试中表现出超过24小时的稳健稳定性，并且在循环伏安法测试中可操作5000个循环。 此外，Ru SAs@PN在0.5mH2SO4溶液中的转换频率（TOF）在25 mV时为1.67 H2s − 1，在50 mV时为4.29 H2s− 1，优于大多数已报道的析氢催化剂。 密度泛函理论（DFT）计算进一步表明，与负载在碳和C3 N4上的Ru/C和Ru SA相比，在PN上的Ru SA上吸附的H* 的吉布斯自由能更接近于零，从而显著促进整体HER性能。
Amorphous phosphorus nitride imide nanotubes (HPN) are reported as a novel substrate to stabilize materials containing single‐metal sites. Abundant dangling unsaturated P vacancies play a role in stabilization. Ruthenium single atoms (SAs) are successfully anchored by strong coordination interactions between the d orbitals of Ru and the lone pair electrons of N located in the HPN matrix. The atomic dispersion of Ru atoms can be distinguished by X‐ray absorption fine structure measurements and spherical aberration correction electron microscopy. Importantly, Ru SAs@PN is an excellent electrocatalyst for the hydrogen evolution reaction (HER) in 0.5mH2SO4, delivering a low overpotential of 24 mV at 10 mA cm−2and a Tafel slope of 38 mV dec−1. The catalyst exhibits robust stability in a constant current test at a large current density of 162 mA cm−2for more than 24 hours, and is operative for 5000 cycles in a cyclic voltammetry test. Additionally, Ru SAs@PN presents a turnover frequency (TOF) of 1.67 H2s−1at 25 mV, and 4.29 H2s−1at 50 mV, in 0.5mH2SO4solution, outperforming most of the reported hydrogen evolution catalysts. Density functional theory (DFT) calculations further demonstrate that the Gibbs free energy of adsorbed H* over the Ru SAs on PN is much closer to zero compared with the Ru/C and Ru SAs supported on carbon and C3N4, thus considerably facilitating the overall HER performance.