物理化学学报2024，Vol.40Issue(3)：48-49,2.DOI:10.3866/PKU.WHXB202305021
强钴―氧键合作用提升缺陷型Co2MnO4酸性析氧反应稳定性
Enhancing Cobalt―Oxygen Bond to Stabilize Defective Co2MnO4 in Acidic Oxygen Evolution
摘要
Abstract
Co-based oxides have shown promise as catalysts for the oxygen evolution reaction(OER),as evidenced by experimental and theoretical studies.However,these common Co-based catalysts suffer from poor stability in acidic environments,making them susceptible to corrosion in acid electrolytes.Consequently,developing OER catalysts that can maintain both activity and stability under strongly acidic conditions is a challenging task for large-scale industrial hydrogen production applications.To address this challenge,the incorporation of manganese(Mn)into the spinel lattice of Co3O4(CoMn1O)has been proposed,resulting in a defect-rich catalyst with improved lifetime in acidic electrolytes.The crystalline phase structures and chemical valence states were investigated using X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),high-resolution transmission electron microscopy(HRTEM),and energy-dispersive spectroscopy(EDS)elemental maps.The introduction of Mn led to the generation of a significant number of defects due to changes in the local crystal structure.Additionally,as the amount of Mn atoms increased,a red shift was observed in the Co 2p spectrum,indicating an increase in the overall valence of Co and the formation of more stable Co―O bonds.Moreover,when the Mn-to-Co ratio reached 1(CoMn1O),the resulting catalyst exhibited promising OER activity,with overpotentials of 415 and 552 mV at 10 and 50 mA·cm-2,respectively.Detailed physical characterization and electrochemical tests demonstrated that CoMn1O exhibited over four times the stability of Mn-free Co3O4(CoMn0O).This enhanced stability can be attributed to the introduction of Mn,which promotes electron density bias of Co towards O,resulting in the formation of more stable Co―O bonds.Mn also facilitates acidic oxygen evolution by delaying the oxidation rate of the Co active sites,thereby enhancing stability.Density functional theory(DFT)calculations were further employed to analyze the electronic structures of CoMn1O and CoMn0O.The d-band center of Co 3d(εd)in CoMn1O shifted closer to the Fermi level(EF)compared to that of CoMn0O,indicating a reduced reaction energy barrier for CoMn1O and enhanced bonding interaction with OER intermediates.Overall,this work presents a promising strategy for achieving highly efficient and stable acidic oxygen evolution using noble-metal-free electrocatalysts.关键词
中空结构/钴锰尖晶石氧化物/钴锰普鲁士蓝类似物/酸性析氧反应Key words
Hollow structure/Cobalt-manganese spinel oxide/CoMn-Prussian blue analogue(PBA)/Acidic OER分类
化学引用本文复制引用
谢静宜,吕千喜,乔韦珍,卜辰宇,张昱声,翟雪君,吕仁庆,柴永明,董斌..强钴―氧键合作用提升缺陷型Co2MnO4酸性析氧反应稳定性[J].物理化学学报,2024,40(3):48-49,2.基金项目
The project was supported by the National Natural Science Foundation of China(52174283),Innovation Fund Project for Graduate Student of China University of Petroleum(East China)(22CX04023A),and the Fundamental Research Funds for the Central Universities.国家自然科学基金(52174283),中国石油大学(华东)研究生创新基金项目(22CX04023A)及中央高校基本科研业务费资助 （52174283）
