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Iridium single-atom catalyst coupled with lattice oxygen activated CoNiO2 for accelerating the oxygen evolution reaction
Journal of Materials Chemistry A ( IF 10.7 ) Pub Date : 2022-11-22 , DOI: 10.1039/d2ta07292k
Meng-Qi Yang 1 , Kai-Ling Zhou 1 , Chao Wang 1 , Man-Chen Zhang 2 , Chang-Hao Wang 1 , Xiaoxing Ke 2 , Ge Chen 3 , Hao Wang 1 , Ru-Zhi Wang 1
Affiliation  

Iridium (Ir) single-atom catalysts (SACs) exhibit extraordinary advantages in the oxygen evolution reaction (OER) owing to their unique electronic structure and maximized atom utilization. However, further developments have met with bottlenecks due to the limited catalytic activity derived from the widely adopted adsorbate evolution mechanism (AEM) pathway in Ir SACs for OER. Herein, we report an efficient strategy to improve the intrinsic activity of Ir SACs by anchoring atomic Ir on an oxygen vacancy-modified CoNiO2 support (IrSA-VO-CoNiO2), in which a more advanced lattice oxygen oxidation (LOM) pathway is constructed by activating lattice oxygen to participate in OER. Specifically, the synthesized CoNiO2 support could provide the weak metal–oxygen bond and facilitate the movement and conversion of lattice oxygen. The oxygen vacancies provided abundant active sites for the adsorption of OH* and induced a substantial O 2p characteristic near the Fermi level for activating the lattice oxygen in CoNiO2. Moreover, the introduction of Ir atoms in the oxygen vacancies modulated CoNiO2 results in the significant overlap between the Ir 5d and O 2p bands and constructed a stronger Ir–O covalent bond, which extremely facilitated the transformation from O–O to OO* for boosting the final O2 evolution. Through the above-mentioned results, a more efficient LOM pathway in the single-atom Ir catalyst was constructed, and the as-synthesized IrSA-VO-CoNiO2 displayed outstanding OER performance with 10 mA cm−2 at a low overpotential of 183 mV and a high mass activity of 5 A mg−1 at the overpotential of 300 mV, significantly outperforming the reported catalysts. This work proposes an advanced channel to design efficient electrocatalysts for promising OER applications.

中文翻译:

铱单原子催化剂偶联晶格氧活化CoNiO2加速析氧反应

铱 (Ir) 单原子催化剂 (SAC) 由于其独特的电子结构和最大化的原子利用率,在析氧反应 (OER) 中表现出非凡的优势。然而,由于在用于 OER 的 Ir SAC 中广泛采用的吸附物演化机制 (AEM) 途径产生的催化活性有限,进一步的发展遇到了瓶颈。在此,我们报告了一种通过将原子 Ir 锚定在氧空位修饰的 CoNiO 2载体(Ir SA -V O -CoNiO 2)上来提高 Ir SAC 内在活性的有效策略,其中更先进的晶格氧氧化(LOM)通路是通过激活晶格氧参与OER构建的。具体而言,合成的 CoNiO 2支撑可以提供弱的金属-氧键并促进晶格氧的移动和转化。氧空位为吸附OH*提供了丰富的活性位点,并在费米能级附近诱导出大量的O 2p 特性,用于激活CoNiO 2中的晶格氧。此外,在调制的 CoNiO 2氧空位中引入 Ir 原子导致 Ir 5d 和 O 2p 带之间的显着重叠并构建更强的 Ir-O 共价键,这极大地促进了从 O-O 到 OO* 的转变促进最终的 O 2进化。通过上述结果,构建了单原子 Ir 催化剂中更有效的 LOM 途径,合成后的 Ir SA -VO -CoNiO 2显示出出色的 OER 性能,在 183 mV 的低过电势下为 10 mA cm -2 ,在 300 mV 的过电势下具有 5 A mg -1的高质量活性,显着优于报道的催化剂。这项工作提出了一个先进的渠道来设计高效的电催化剂,用于有前途的 OER 应用。
更新日期:2022-11-22
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