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基于高氧空位浓度和高Ni3+/Ni2+比值NiO电催化剂实现甲醇电催化氧化增强

卢剑天1,赵曼帧1,张保华1,宋爽2,张玉微1,2   

  1. 1. 广州大学
    2. 华南师范大学
  • 收稿日期:2025-03-14 修回日期:2025-04-09 网络首发:2025-04-16 发布日期:2025-04-16
  • 通讯作者: 张玉微 E-mail:ywzhang@scnu.edu.cn
  • 基金资助:
    国家自然科学基金(批准号:22122402)、广东省自然科学基金(批准号:2021B1515020048, 2023A1515010623)和广东省科技创新战略专项基金(批准号:pdjh2024b303)资助

Enhancing Methanol Oxidation Reaction by NiO Featuring High Concentration of Oxygen Vacancy and Ni3+/Ni2+ Ratio

LU Jiantian1, ZHAO Manzhen1, ZHANG Baohua1, SONG Shuang2, ZHANG Yuwei1,2   

  1. 1. Guangzhou University 2. South China Normal University
  • Received:2025-03-14 Revised:2025-04-09 Online First:2025-04-16 Published:2025-04-16
  • Contact: Yu-Wei ZHANG E-mail:ywzhang@scnu.edu.cn
  • Supported by:
    Supported by the National Natural Science Foundation of China(No. 22122402), the Natural Science Foundation of Guangdong Province, China(Nos. 2021B1515020048, 2023A1515010623) and the Science and Technology Innovation Strategy of Guangdong Province, China(No. pdjh2024b303)

摘要: 针对镍基电催化剂在甲醇氧化反应(MOR)中活性位点不足、导电性差和催化反应动力学速度慢等瓶颈问题,本研究通过晶格掺杂工程策略,采用低成本钼酸铵前驱体结合煅烧工艺,成功构建了氧空位与Ni3+活性位点协同增强的Mo掺杂NiO催化剂。实验结果表明:随着Mo掺杂量从0增加至28 at %,催化剂表面氧空位浓度由30.18 %梯度提升至56.59 %,Ni3+物种占比从65.55%增至85.91 %;当Mo掺杂量为28 at %时,在1.0 M KOH/1.0 M CH3OH电解液中,1.7 V vs. RHE电位下获得280.8 mA·cm-2的电流密度,较未掺杂NiO(21.7 mA·cm-2)提升12.9倍,Tafel斜率由63 mV·dec?1显著降低至25 mV·dec-1。该文通过XRD、SEM、TEM、XPS的系统表征,还对Mo掺杂制备氧空位浓度和Ni3+/Ni2+比值可调变的NiO催化剂的形成机制和MOR电催化效果展开详细研究,初步揭示了其背后的原理和构效关联。该工作将为设计具有高活性位点浓度的高效DMFC阳极催化剂提供了新思路。

关键词: 氧空位, 甲醇氧化反应, 钼掺杂

Abstract: To address the critical challenges of insufficient active sites, poor conductivity, and sluggish reaction kinetics in nickel-based electrocatalysts for methanol oxidation reaction (MOR), this study proposes a lattice doping engineering strategy. By employing a low-cost ammonium molybdate precursor coupled with a calcination process, we successfully constructed Mo-doped NiO catalysts synergistically enhanced by oxygen vacancies and Ni3? active sites. Experimental results demonstrate that as the Mo doping level increases from 0 to 28 at%, the oxygen vacancy concentration on the catalyst surface escalates progressively from 30.18% to 56.59%, while the proportion of Ni3+ species rises from 65.55% to 85.91%. At an optimal Mo doping content of 28 at%, the catalyst achieves a current density of 280.8 mA·cm?2 at 1.7 V vs. RHE in 1.0 M KOH/1.0 M CH?OH electrolyte, representing a 12.9-fold enhancement compared to undoped NiO (21.7 mA·cm-2). Furthermore, the Tafel slope decreases significantly from 63 mV·dec?1 to 25 mV·dec?1. Systematic characterizations via XRD, SEM, TEM, and XPS elucidate the formation mechanism of Mo-doped NiO catalysts with tunable oxygen vacancy concentrations and Ni3?/Ni2? ratios, as well as their MOR electrocatalytic performance. A preliminary structure-activity relationship is established, revealing the underlying principles of enhanced activity. This work provides a novel approach for designing efficient anode catalysts for direct methanol fuel cells (DMFCs) with high active site density.

Key words: Oxygen vacancy, MOR, Mo-doping

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