APPLIED SURFACE SCIENCE
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2024
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IF 6.3
Jinwei Qin,Peng Zhao,Jie Meng,Shixiang Zuo,Xiaohui Wang,Wei Zhu,Wenjie Liu,Jingwei Liu,Chao Yao
Higher specific surface area and abundant surface oxygen vacancies are considered to be essential to the catalytic combustion. Herein, we elaborately fabricated an innovative catalyst on the basis of LaMnO 3 @Co 2 MnO 4 under a controllable selective dissolution (SD) treatment for ethane catalytic combustion. La element in perovskite could effectively protect the spinel system as a sacrifice, with MnO 2 covering on the spinel surface, thereby enhancing the activity and stability. In combination with XPS, in-situ DRIFT and various characterization results, this acid corrosion could provide induce better reducibility, larger specific surface area, higher Mn 4+ and Co 3+ content and more oxygen vacancies , which played a significant role in promoting the adsorption, activation and decomposition of ethane. Among all as-prepared catalysts, the optimal performance for catalytic ethane combustion was achieved on LMO@CMO-10 catalyst. The T 90 of LMO@CMO-10 was 341 °C under space velocity of 80,000 mL·g −1 ·h −1 . This work not only fabricated the catalyst system with higher specific surface area and more oxygen vacancy by SD method, but also provided a potential strategy for the preparation of highly active catalysts.
研究领域:
材料科学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2023
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IF 15.1
Jing Li,Xiyu He,Yunzhu Du,Min Jiang,Qiaodan Hu,Jiewei Yin,Fan Yang,Junliang Zhang
Co/Mn-based spinel oxides are promising electrocatalysts for both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), however, it is challenging to achieve high activities for ORR and OER simultaneously in one composition. Here, we report Co 2 MnO 4 (C2M) with Mn-rich surfaces and abundant twin defects synthesized by a simple coprecipitation and annealing route, which exhibits excellent ORR activity (half-wave potential E 1/2 = 0.830 V), long ORR durability (91% current retained after 12 h-chronoamperometry test at 0.45 V vs. RHE) and a low Δ E = 0.767 V between E 1/2 and E 10 mA/cm 2 in alkaline electrolyte, which enables its excellent performances in rechargeable Zn-air batteries showing a high peak energy density of 136 mW/cm 2 and a large specific capacity of 809.4 mAh/g Zn . Combining comprehensive experimental investigations and DFT simulations, we reveal that the Mn-rich surfaces benefit bridge adsorption of O 2 to promote the 4-electron reaction pathway in ORR, and the mixed site occupancy in the crystal structure induces Mn/Co-O orbital hybridizations to form an impurity energy level in the band gap to facilitate charge transfer. Furthermore, the bifunctional performance and the ORR durability can be further enhanced by acid treatment to show a lower Δ E = 0.750 V and to retain 98.5% ORR current in 12 h. This work provides not only a promising bifunctional electrocatalyst but also a new perspective of exploring simple synthesis method suitable for mass-producible electrocatalysts with highly active surfaces.
研究领域:
电化学
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材料科学
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能源存储
✓ 已验证
产品关联
DOI
高影响因子
ChemCatChem
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2024
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IF 3.8
Zhi Wang,Zhaokun Wang,Wenxin Li,Jiashuai Wang,Haofeng Shi,Chengdeng Wang,Zhiming Bai,Yan Gao,Chuang Zhu,Xiaoqin Yan
Graphical In this study, an effective technique for synthesizing Nitrogen Doped Carbon Layer Coated Co 2 MnO 4 was introduced. The Nitrogen doped carbon layer derived from graphene decreases the electronic transmission resistance, optimize surface electron distribution and enhances the formation of the CoOOH active phase during the initial oxygen evolution reaction (OER) process, achieving 100 mA/cm 2 at 1.56 V vs. RHE. Electrocatalysts for the oxygen evolution process must be both active and stable in order to make hydrogen from water using renewable power. Nitrogen-doped carbon layer coated cobalt manganate particles were synthesized on carbon cloth using calcination method. The catalysts exhibited small particle sizes and graphitized carbon layer that covered the cobalt manganate, facilitating electron flow. Moreover, the nitrogen-doped carbon layer enhanced the oxygen evolution reaction (OER) rate by reducing the potential required for surface reconstruction and optimizing electron distribution on the cobalt manganate surface. This electrocatalyst demonstrated a current density of 100 mA/cm 2 at 1.56 V vs. RHE. Thus, this electrocatalyst shows promise as a novel OER catalyst for water oxidation in acidic aqueous solutions.
研究领域:
材料科学
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电化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Water Process Engineering
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2023
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IF 7
Lijuan Yue,Liangyun Hao,Junkai Zhang,Xijun Piao,Chunguang Chen
Spinel is a desirable catalyst for active peroxymonosulfate (PMS) to degrade organic pollutants in complex water matrix. In this study, spinel-type Co 2 MnO 4 catalyst were successfully synthesized and employed as an efficient PMS activator for the degradation of phenol in water (up to 100 % within 45 min, degradation rate constant (k) is 0.076 min −1 ) at initial PH of 6.3. The excellent catalytic activity of Co 2 MnO 4 /PMS system was found to be attributed to its unique porous structure, oxygen vacancies and the synergistic effect of Co and Mn. Sulfate radicals (SO 4 − ) and singlet oxygen ( 1 O 2 ) all contributed to phenol degradation, and 1 O 2 , a non-radical pathway mainly provided by oxygen vacancies of Co 2 MnO 4 , is the dominant reactive species in the activation system. The Co 2 MnO 4 /PMS system had good resistance to the common inorganic anions (Cl − , HPO 4 2− , HCO 3 − and NO 3 − ) and exhibited great reusability due to the strong Co/Mn interaction. Finally, the phenol degradation mechanism in Co 2 MnO 4 /PMS system was also proposed based on the detected intermediates by GC–MS. Overall, the system composed of oxygen-enriched vacancy Co 2 MnO 4 spinel catalyst and PMS has good degradation efficiency and is suitable for the remediation of organic pollutants in wastewater.
研究领域:
环境科学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
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2021
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IF 6.707
Ru-Lan Zhang,Jiu-Ju Feng,You-Qiang Yao,Ke-Ming Fang,Lu Zhang,Zheng-Zhi Yin,Ai-Jun Wang
Developing high-performance and cut-price non-noble-metal electrocatalysts for hydrogen evolution reaction (HER) is desirable yet challenging. Herein, straw-like phosphorus-doped Co 2 MnO 4 nanoneedle arrays supported on nickel foam (P-Co 2 MnO 4 /NF) were prepared by successive hydrothermal treatment, oxidation and P doping for high-efficiency HER. Benefiting from the unique needle-like arrays and compositions advantages, P-Co 2 MnO 4 /NF exhibited excellent HER activities with the overpotentials of 33, 43 and 102 mV to afford a current density of 10 mA cm −2 in alkaline, acidic and neutral media, respectively, coupled with the long-term electrochemical stability. This work affords an effective avenue for preparation of cost-effectiveness, high-efficiency and wide-pH HER catalysts for electrochemical energy technologies.
研究领域:
材料科学
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电化学
✓ 已验证
产品关联
DOI
高影响因子
CHINESE JOURNAL OF ANALYTICAL CHEMISTRY
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2023
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IF 1.2
Yuan-Yuan LI,Yong-Li WU,Na CHEN,Yu-Long MA,Wen-Xin JI,Yong-Gang SUN
In this study, metal composite oxides grown on nickel foam were prepared, which were modified by dopamine and biochar to obtain cauliflower-shaped Co 2 MnO 4 /NF@PDA/BC adsorption material to adsorb cationic dyes from aqueous solutions. The maximum adsorption amounts q max for methylene blue (MB), malachite green (MG), and crystal violet (CV) were 8.44, 41.03 and 3.39 mg g − 1 , and the adsorption aligned with the Langmuir isothermal model as single molecular layer adsorption on a homogeneous surface. The adsorption experiments of dyes were conducted using lake water in the environment, and the adsorption rates of MB, MG, and CV were 91.4%, 94.8% and 85.1%, respectively. Meanwhile, the material has wide pH applicability (3–9), and good adsorption-desorption cycle performance. In addition, the synthesized adsorbent Co 2 MnO 4 /NF@PDA/BC and the control adsorbent were investigated and shown to have good adsorption capacity. In conclusion, the adsorbent materials synthesized in this work have some application prospects in dye wastewater adsorption.
研究领域:
环境科学
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材料科学
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水处理
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）