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Iridium Single Atoms Coupling with Oxygen Vacancies Boosts Oxygen Evolution Reaction in Acid Media
Journal of the American Chemical Society ( IF 14.4 ) Pub Date : 2020-09-21 , DOI: 10.1021/jacs.0c05050
Jie Yin 1 , Jing Jin 1 , Min Lu 1 , Bolong Huang 2 , Hong Zhang 3 , Yong Peng 3 , Pinxian Xi 1 , Chun-Hua Yan 1, 4
Affiliation  

Simultaneous realization of improved activity, enhanced stability, and reduced cost remains a desirable yet challenging goal in the search of electrocatalysis oxygen evolution reaction (OER) in acid. Herein, we report a novel strategy to prepare iridium single-atoms (Ir-SAs) on ultrathin NiCo2O4 porous nanosheets (Ir-NiCo2O4 NSs) by co-electrodeposition method. The surface exposed Ir-SAs couplings with oxygen vacancies (VO) exhibit boosting the catalysts OER activity and stability in acid media. They display superior OER performance with an ultralow overpotential of 240 mV at j = 10 mA cm-2 and long-term stability of 70 h in acid media. The TOFs of 1.13 and 6.70 s-1 at an overpotential of 300 and 370 mV also confirm their remarkable performance. Density functional theory (DFT) calculations reveal that the prominent OER performance arises from the surface electronic exchange-and-transfer activ-ities contributed by atomic Ir incorporation on the intrinsic VO existed NiCo2O4 surface. The atomic Ir sites substantially elevate the electronic activity of surface lower coordinated Co-sites nearby VO, which facilitate the surface electronic exchange-and-transfer capabilities. With this trend, the preferred H2O-activation and stabilized *O have been reached towards competitively lower overpo-tential. This is a generalized key for optimally boosting OER performance.

中文翻译:

铱单原子与氧空位的耦合促进了酸性介质中的析氧反应

同时实现提高的活性、增强的稳定性和降低的成本仍然是寻找酸中电催化析氧反应 (OER) 的理想但具有挑战性的目标。在此,我们报告了一种通过共电沉积方法在超薄 NiCo2O4 多孔纳米片(Ir-NiCo2O4 NSs)上制备铱单原子(Ir-SAs)的新策略。表面暴露的 Ir​​-SAs 与氧空位 (VO) 偶联表现出提高了催化剂在酸性介质中的 OER 活性和稳定性。它们显示出卓越的 OER 性能,在 j = 10 mA cm-2 时具有 240 mV 的超低过电位和在酸性介质中 70 小时的长期稳定性。在 300 和 370 mV 的过电位下,1.13 和 6.70 s-1 的 TOF 也证实了它们的卓越性能。密度泛函理论 (DFT) 计算表明,显着的 OER 性能源于表面电子交换和转移活性,这是由原子 Ir 结合在固有的 VO 存在的 NiCo2O4 表面上贡献的。原子 Ir 位点大大提高了 VO 附近表面较低配位的 Co-sites 的电子活性,这促进了表面电子交换和转移能力。在这种趋势下,首选的 H2O 活化和稳定的 *O 已达到具有竞争力的低超电势。这是优化提高 OER 性能的通用密钥。原子 Ir 位点大大提高了 VO 附近表面较低配位的 Co-sites 的电子活性,这促进了表面电子交换和转移能力。在这种趋势下,首选的 H2O 活化和稳定的 *O 已达到具有竞争力的低超电势。这是优化提高 OER 性能的通用密钥。原子 Ir 位点大大提高了 VO 附近表面较低配位的 Co-sites 的电子活性,这促进了表面电子交换和转移能力。在这种趋势下,首选的 H2O 活化和稳定的 *O 已达到具有竞争力的低超电势。这是优化提高 OER 性能的通用密钥。
更新日期:2020-09-21
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