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Integrating Atomically Dispersed Ir Sites in MnCo2O4.5 for Highly Stable Acidic Oxygen Evolution Reaction
ACS Catalysis ( IF 11.3 ) Pub Date : 2024-02-21 , DOI: 10.1021/acscatal.3c06243
Kang Hua 1 , Xiaoke Li 1 , Zhiyan Rui 1 , Xiao Duan 1 , Yongkang Wu 1 , Deren Yang 2 , Jia Li 2 , Jianguo Liu 2
ACS Catalysis ( IF 11.3 ) Pub Date : 2024-02-21 , DOI: 10.1021/acscatal.3c06243
Kang Hua 1 , Xiaoke Li 1 , Zhiyan Rui 1 , Xiao Duan 1 , Yongkang Wu 1 , Deren Yang 2 , Jia Li 2 , Jianguo Liu 2
Affiliation
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Industrial water electrolysis requires oxygen evolution reaction (OER) catalysts that exhibit both high activity and adaptability to high current densities. However, single Ir atoms of the OER catalysts often show high performance in the three-electrode system but are limited to low current densities in proton exchange membrane water electrolyzers (PEMWE). The high oxidation potential and catalyst shedding caused by oxygen bubble desorption have hindered the stability, resulting in unsatisfactory PEMWE performance. Achieving high catalytic stability under high current density conditions still presents a significant challenge for all of the OER catalysts. In this study, an efficient and stable catalytic system for OER is constructed by a doping strategy, which consists of atomically dispersed Ir sites in MnCo2O4.5. The integrated Ir–MnCo2O4.5 catalyst demonstrates remarkable OER activity, with a low overpotential of 238 mV at 10 mA/cm2. It exhibits long-term stability, maintaining this high activity for 700 h at 20 mA/cm2 with a degradation rate of 0.025 mV/h. Impressively, the PEMWE with the integrated Ir–MnCo2O4.5 as the anode remains stable even after nearly 100 h at 200 mA/cm2, outperforming most previously reported single-iridium atom-based PEMWEs. Density functional theory calculations show that the redistribution of charges brought by the introduction of Ir and Mn not only effectively reduces the dissolution of lattice oxygen and Ir active sites but also lowers the energy barrier of the rate-determining step, thereby significantly improving the stability and activity of Ir–MnCo2O4.5 under high current density.
中文翻译：
将原子分散的 Ir 位点整合到 MnCo2O4.5 中以实现高度稳定的酸性析氧反应
工业水电解需要析氧反应 (OER) 催化剂，该催化剂必须具有高活性和对高电流密度的适应性。然而，OER 催化剂的单 Ir 原子通常在三电极系统中表现出高性能，但仅限于质子交换膜水电解槽 (PEMWE) 中的低电流密度。氧气气泡解吸引起的高氧化电位和催化剂脱落阻碍了稳定性，导致PEMWE性能不理想。在高电流密度条件下实现高催化稳定性仍然对所有 OER 催化剂提出重大挑战。在本研究中，通过掺杂策略构建了高效稳定的OER催化体系，该体系由MnCo 2 O 4.5中原子分散的Ir位点组成。集成的Ir-MnCo 2 O 4.5催化剂表现出显着的OER活性，在10 mA/cm 2下具有238 mV的低过电势。它表现出长期稳定性，在 20 mA/cm 2下保持这种高活性 700 小时，降解率为 0.025 mV/h。令人印象深刻的是，以集成Ir–MnCo 2 O 4.5作为阳极的PEMWE即使在200 mA/cm 2电流下经过近100小时后仍保持稳定，优于大多数先前报道的基于单铱原子的PEMWE。密度泛函理论计算表明，Ir和Mn的引入带来的电荷重新分布不仅有效减少了晶格氧和Ir活性位点的溶解，而且降低了速率决定步骤的能垒，从而显着提高了稳定性和稳定性。高电流密度下Ir–MnCo 2 O 4.5的活性。
更新日期：2024-02-21
中文翻译：
将原子分散的 Ir 位点整合到 MnCo2O4.5 中以实现高度稳定的酸性析氧反应
工业水电解需要析氧反应 (OER) 催化剂，该催化剂必须具有高活性和对高电流密度的适应性。然而，OER 催化剂的单 Ir 原子通常在三电极系统中表现出高性能，但仅限于质子交换膜水电解槽 (PEMWE) 中的低电流密度。氧气气泡解吸引起的高氧化电位和催化剂脱落阻碍了稳定性，导致PEMWE性能不理想。在高电流密度条件下实现高催化稳定性仍然对所有 OER 催化剂提出重大挑战。在本研究中，通过掺杂策略构建了高效稳定的OER催化体系，该体系由MnCo 2 O 4.5中原子分散的Ir位点组成。集成的Ir-MnCo 2 O 4.5催化剂表现出显着的OER活性，在10 mA/cm 2下具有238 mV的低过电势。它表现出长期稳定性，在 20 mA/cm 2下保持这种高活性 700 小时，降解率为 0.025 mV/h。令人印象深刻的是，以集成Ir–MnCo 2 O 4.5作为阳极的PEMWE即使在200 mA/cm 2电流下经过近100小时后仍保持稳定，优于大多数先前报道的基于单铱原子的PEMWE。密度泛函理论计算表明，Ir和Mn的引入带来的电荷重新分布不仅有效减少了晶格氧和Ir活性位点的溶解，而且降低了速率决定步骤的能垒，从而显着提高了稳定性和稳定性。高电流密度下Ir–MnCo 2 O 4.5的活性。
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