Stabilizing the OOH* intermediate via pre-adsorbed surface oxygen of a single Ru atom-bimetallic alloy for ultralow overpotential oxygen generation,Energy & Environmental Science

当前位置： X-MOL 学术 › Energy Environ. Sci. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Stabilizing the OOH* intermediate via pre-adsorbed surface oxygen of a single Ru atom-bimetallic alloy for ultralow overpotential oxygen generation
Energy & Environmental Science ( IF 32.4 ) Pub Date : 2020-11-04 , DOI: 10.1039/d0ee03183f
Jinsun Lee _{1,

2,

3,

4,

5} , Ashwani Kumar _{1,

2,

3,

4,

5} , Taehun Yang _{1,

2,

3,

4,

5} , Xinghui Liu _{1,

2,

3,

4,

5} , Amol R Jadhav _{1,

2,

3,

4} , G. Hwan Park _{1,

2,

3,

4,

5} , Yosep Hwang _{1,

2,

3,

4,

5} , Jianmin Yu _{1,

2,

3,

4,

5} , Chau TK Nguyen _{1,

2,

3,

4,

5} , Yang Liu _{1,

2,

3,

4,

5} , Sara Ajmal _{1,

2,

3,

4,

5} , Min Gyu Kim _{4,

6,

7,

8,

9} , Hyoyoung Lee _{1,

2,

3,

4,

5}

Affiliation

Designing efficient oxygen evolution reaction (OER) electrocatalysts based on single-atom catalysts is a highly promising option for cost-effective alkaline water electrolyzers. However, the instability of the OOH* intermediate and high energy barrier for the rate-determining step (RDS) (O* to OOH*) on the pure bimetallic-alloy represent serious challenges. Here, we report atomically dispersed Ru single-atoms on a cobalt–iron bimetallic-alloy encapsulated by graphitic carbon (Ru_SACoFe₂/G) as an efficient and durable electrocatalyst for the alkaline OER. In-depth X-ray absorption spectroscopy (XAS) and aberration-corrected transmission electron microscopy (AC-TEM) along with theoretical calculations were employed to validate the isolated Ru sites in the surface-oxygen rich alloy. Ru_SACoFe₂/G displays exceptional intrinsic activity, achieving a record low overpotential of only 180 mV at 10 mA cm⁻² with superior durability in alkali media. Density functional theory (DFT) simulations revealed that the isolated Ru sites with pre-adsorbed surface oxygen species on a bimetallic-alloy efficiently stabilize the OOH* intermediate and significantly reduce the energy barrier for the RDS, boosting the intrinsic OER activity. Our integrated alkaline electrolyzer demands a low cell voltage of 1.48 V at 10 mA cm⁻², suggesting that it has potential for use in practical applications.

中文翻译：

通过单一Ru原子-双金属合金的预吸附表面氧稳定OOH *中间体，以产生超低的超电势氧

对于具有成本效益的碱性水电解槽而言，设计基于单原子催化剂的高效氧气析出反应（OER）电催化剂是非常有前途的选择。但是，纯双金属合金上用于速率确定步骤（RDS）（从O *到OOH *）的OOH *中间层和高能垒的不稳定性是严峻的挑战。在这里，我们报告了原子-分散的钌单原子在被石墨碳（Ru _SA CoFe ₂ / G）封装的钴-铁双金属合金上作为碱性OER的有效和持久的电催化剂。深入的X射线吸收光谱（XAS）和像差校正的透射电子显微镜（AC-TEM）以及理论计算被用来验证表面富氧合金中孤立的Ru位。茹_SA CoFe₂ / G具有出色的固有活性，在10 mA cm^-2时仅180 mV的创纪录低过电势，在碱性介质中具有出色的耐久性。密度泛函理论（DFT）模拟表明，在双金属合金上具有预吸附表面氧物种的孤立Ru位点有效地稳定了OOH *中间体，并显着降低了RDS的能垒，从而提高了OER的固有活性。我们的集成式碱性电解槽在10 mA cm^-2时需要1.48 V的低电池电压，这表明它具有在实际应用中使用的潜力。

更新日期：2020-11-25

点击分享查看原文

点击收藏

阅读更多本刊最新论文本刊介绍/投稿指南11