ACS Nano
·
2024
·
IF 15.8
Qingming Deng,Hui Li,Ke Pei,Lok Wing Wong,Xiaodong Zheng,Chi Shing Tsang,Honglin Chen,Wenqian Shen,Thuc Hue Ly,Jiong Zhao,Qiang Fu
High-efficiency catalysts with refined electronic structures are highly desirable for promoting the kinetics of the oxygen evolution reaction (OER) and enhancing catalyst durability. This study comprehensively explores strategies involving metal doping and oxygen vacancies for enhancing the acidic OER catalytic activity of Co3O4. Through extensive screening of 3d and 4d transition metals using density functional theory (DFT) simulations, we demonstrate that the incorporation of metal dopants and oxygen vacancies into Co3O4 potentially triggers a transition from the adsorbate evolution mechanism (AEM) to the lattice oxygen oxidation mechanism (LOM) in the oxygen evolution reaction (OER). While the formation of the O–O bond in the intermediate *OOH poses challenges, a significantly reduced overpotential facilitates efficient conversion of O to O2 through the LOM in *OH and lattice oxygen. Additionally, we find that Mn doping can significantly improve the stability of the catalyst. Building upon the rationale above, we employed a dual doping strategy in subsequent experiments to enhance both the activity and stability. Our final design involved the codoping of Mn and Ru in Co3O4, along with an appropriate amount of oxygen vacancies. This catalyst demonstrates a low overpotential (η10 = 230 mV) compared to pure Co3O4 and maintains stable operation for over 120 h, representing a 12-fold increase. By exploring and harnessing the LOM, more efficient, stable, and cost-effective OER catalysts can be designed, providing crucial support for technologies such as water electrolysis in clean energy.
研究领域:
材料科学
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催化化学
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清洁能源技术
✓ 已验证
DOI
PubMed
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2018
·
IF 11.698
Ke Li,Rongrong Zhang,Ruijie Gao,Guo-Qiang Shen,Lun Pan,Yunduo Yao,Kaihui Yu,Xiangwen Zhang,Ji-Jun Zou
Manganese-cobalt spinel oxides are considered as a class of promising and low-cost electrocatalysts for oxygen reduction reaction (ORR), whose performances largely depend on their electronic structures which can be effectively optimized by defect engineering. Herein, metal defects (manganese vacancies and cobalt vacancies, i.e. V Mn and V Co ) were in-situ introduced into spinel Mn x Co 3-x O 4 via a simple solvothermal treatment followed by thermal calcination. Mn-Co glycerolate precursors not only enable controllable synthesis of spinel oxides with variable metallic ratios, but also play a key role in constructing metal defected crystals for their lamellated structure. As a result of the formation rate difference between manganese and cobalt glycerolate, a unique Mn-enriched surface is formed, leading to the increase of highly active sites for ORR. Importantly, the presence of metal defects, confirmed by XRD (X-ray diffraction), element analysis and XAFS (X-ray absorption fine structure spectroscopy), leads to greatly increased electrical conductivity and O 2 adsorption ability, thus bringing about enhanced ORR activity. Especially, metal-defected Mn 1.5 Co 1.5 O 4 , with the optimal Mn/Co ratio, exhibits comparable activity and superior durability to those of the benchmark Pt/C in ORR and displays excellent discharge performance in Zn-air batteries for practical application. This work provides a new way to optimize the electrocatalytic performance of mixed metal spinel oxides via rational defect engineering.
研究领域:
材料科学
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电化学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2025
·
IF 5.4
Changyue Liang,Song Wu,Guangyin Fan,Xiaojun Yu
Co-based catalysts have demonstrated significant potential for degrading antibiotic contaminants through peroxymonosulfate (PMS) activation. However, difficulties in separation and high ion leaching rates inhibit practical application. Herein, we develop a stable and easily recyclable hybrid catalyst that integrates Ru-doped Co spinel oxide with nickel foam (Ru-Co 3 O 4 /NF) via electrodeposition and calcination. The incorporation of Ru effectively adjusts the molar ratio of Co 2+ to Co 3+ in Co 3 O 4 , resulting in an abundance of Co 2+ that efficiently activate PMS for tetracycline (TC) degradation. Under optimal conditions, Ru-Co 3 O 4 /NF achieves a TC removal rate of 96.6 % within 30 min and demonstrates broad degradation capabilities for various organic pollutants. The Ru-Co 3 O 4 /NF/PMS system operates effectively under diverse conditions, including the presence of inorganic ions and organic matter, as well as across different solution pH levels. Quenching experiments and electron paramagnetic resonance results indicate that the Ru-Co 3 O 4 /NF/PMS system involves both radical and non-radical pathways, with SO 4 •− playing a significant role. The degradation of TC follows three reaction pathways through fourteen intermediates. The toxicity of the original TC is significantly reduced following the degradation process. The present work presents a useful strategy to modulate the electronic structure of spinel oxide for activating PMS to eliminate organic pollutants.
研究领域:
环境科学
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催化
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材料科学
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水处理
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纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Nature Communications
·
2025
·Vol. 16
·期 1
·1-13
·
IF 15.7
Liu Shenning,Wang Yuxian,Liu Ya,Chen Peihan,Kong Tao,Duan Xiaoguang,Chen Chunmao,Sun Hongqi,Wang Shaobin
Cobalt-containing spinel oxides are promising platforms to fine-tune the intrinsic activity/selectivity of their geometric sites in catalysis. However, the role of tetrahedrally occupied Co 2+ (Co 2+ Td ) and Co 3+ in an octahedral site (Co 3+ Oh ) in controlling the catalytic activity remains controversial. Herein, we investigated a geometrical-site-dependent catalytic activation of ozone respectively on the Co 2+ Td and Co 3+ Oh sites. The same exposure of [111] crystal facet is achieved by substituting those undesired sites with catalytically inactive cations. The highly spin-polarized Co 2+ Td sites invoke strong orbital interactions and intensive electron transfer with the adsorbed O 3 and become the active sites for selectively producing surface-bound hydroxyl radicals ( • OH) and avoiding the formation of unfavorable singlet oxygen ( 1 O 2 ), resulting in a 17.6-fold increase in turnover frequency (TOF). This work enlightens the spin-polarized electronic states into regulating the reaction thermodynamics in transition metal oxide-induced catalysis and envisages the practical application potentials of geometric site engineered spinel oxides.
研究领域:
催化化学
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材料化学
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表面科学
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物理化学
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环境科学
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无机化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
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