Ultrafine and Ligand-Free Precious Metal (Ru, Ag, Au, Rh and Pd) Nanoclusters Supported on Phosphorus-Doped Carbon
Ultrafine and Ligand-Free Precious Metal (Ru, Ag, Au, Rh and Pd) Nanoclusters Supported on Phosphorus-Doped Carbon
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DOI：
10.1002/chem.201705504
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发表时间：
2018-02-21
影响因子：
4.3
通讯作者：
He, Jie
中科院分区：
文献类型：
--
作者：
Liu, Ben;Jin, Lei;He, Jie
我们报道了使用磷掺杂的碳（P-C）作为支撑物，通过化学还原生长超小（1-3 nm）和无配体的贵金属纳米晶体（PMNC）。我们发现，表面磷物种的价态是至关重要的，在调整碳载体和金属前体之间的亲和力，合理地控制负载的大小和所得PMNCs的均匀性。原位生长了Ru、Ag、Au、Rh和Pd等五种PMNCs，以证明P-C载体上表面磷位的关键作用。作为概念验证应用，检查了负载在P-C上的平均直径为1.0 +/- 0.2 nm的Ru纳米催化剂用于电催化析氢反应（HER）。超小和无配体的Ru纳米催化剂表现出上级的HER活性和稳定性相比，其对应物与表面剂或更大的尺寸。在电流密度为10 mA·cm ~（-2）时，Ru纳米催化剂的过电位为27.6 mV（相对于可逆氢电极）。这种新的方法开辟了一条新的途径，以无配体和良好分散的PMNCs的碳;更重要的是，它提供了一个新的库支持PMNCs具有高催化活性。
We report the use of phosphorus-doped carbon (P-C) as support to grow ultrasmall (1-3 nm) and ligand-free precious metal nanocrystals (PMNCs) via chemical reduction. We show that the valence states of surface phosphorus species are critical in tuning the affinity between the carbon support and metal precursors, which rationally controls the loading size and uniformity of resultant PMNCs. Five kinds of PMNCs, including Ru, Ag, Au, Rh, and Pd, were grown in situ to demonstrate the key role of surface phosphorus sites on the P-C support. As a proof-of-concept application, Ru nanocatalysts with an average diameter of 1.0 +/- 0.2 nm supported on P-C were examined for the electrocatalytic hydrogen evolution reaction (HER). Ultrasmall and ligand-free Ru nanocatalysts exhibited superior HER activity and stability compared to its counterparts with surface agents or larger sizes. An overpotential of 27.6 mV (vs. reversible hydrogen electrode) for Ru nanocatalysts was achieved at a current density of 10 mA cm(-2). This novel method opens a new avenue to immobilize ligand-free and well-dispersed PMNCs on carbon; and, more importantly, it provides a new library of supported PMNCs with high catalytic activity.