Mn掺杂Co3O4电催化剂的制备及析氧反应性能研究

Preparation and Performance of Mn-Doped Co3O4 Electrocatalysts for Oxygen Evolution Reaction

摘要:

氢能对于缓解能源危机和环境污染意义重大。电化学水分解过程中，阳极析氧反应（OER）作为能量转换装置的关键半反应，由于电子-质子转移形成了复杂的中间产物，导致动力学缓慢，限制了产氢速率。传统OER催化剂包括二氧化铱、二氧化钌等贵金属，存在储量低、价格昂贵、稳定性差等缺点，因此设计开发高效、廉价的非贵金属OER催化剂是解决OER动力学缓慢问题的关键。尖晶石氧化物（AB₂O₄）具有特殊的电子结构和优异的OER 性能，并可通过杂元素原子掺杂进一步提高其OER性能，被认为是一种具有潜力的非贵金属电催化剂。采用一步水热法，合成了Mn掺杂Co₃O₄电催化剂Mn-Co₃O₄，研究了其电催化性能和稳定性。结果表明，利用Mn原子的掺杂，构建了氧桥连的Mn-O-Co配位结构，通过协同耦合作用，提高了Mn-Co₃O₄的OER催化性能。制备的Mn-Co₃O₄ 催化剂表现出高效的催化活性，在电流密度10和100 mA?cm^-2下，其过电位分别为 270和335 mV。Mn-Co₃O₄同时表现出快速的动力学性能，Tafel斜率低至74 mV?dec^-1。此外，Mn-Co₃O₄还具有优异的稳定性，在电流密度10 mA?cm^-2下可稳定保持40 h。本研究为开发高效的OER催化剂提供了思路 。

Abstract:

Hydrogen energy holds significant importance in alleviating energy crises and environmental pollution. The sluggish kinetics of the oxygen evolution reaction（OER）in electrochemical water splitting limits the rate of hydrogen production，thus the development of efficient OER catalysts is crucial to promote the rapid progress of the water splitting process. In catalyst selection，spinel oxides are considered as promising non-precious metal electrocatalysts due to their unique electronic structure and excellent OER performance. Atomic doping design is the most feasible strategy to enhance the OER performance of spinel oxides. Results demonstrate that the Mn-doped Co₃O₄ electrocatalyst synthesized via a one-step hydrothermal method，by introducing Mn atoms，constructs an oxygen-bridged Mn-O-Co coordination structure，thereby enhancing the OER catalytic performance of Mn-Co₃O₄ through synergistic coupling effects. The prepared Mn-Co₃O₄ exhibits efficient catalytic activity，with overpotentials of 270 and 335 mV at current densities of 10 and 100 mA·cm^-2，respectively；moreover，Mn-Co₃O₄ demonstrates rapid kinetic performance with a Tafel slope as low as 74 mV?dec^-1. Additionally，Mn-Co₃O₄ displays excellent stability，maintaining stability for up to 40 h at a current density of 10 mA?cm^-2. This study provides insights for the development of efficient OER catalysts.