在MnO2上加载IrO集群通过金属支相互作用促进酸性水的氧化
Yunchu Zeng1, Li Yan1, Shubo Tian1
1State Key Laboratory of Chemical Resource Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing 100029, China.
ACS applied materials & interfaces
|September 29, 2023
概括
这项研究在二氧化 (MnO2) 纳米片上开发了高效的氧化 (IrO2) 纳米集群,用于酸性水的氧化,这是绿色生产的关键步骤. 与其他相相相比,IrO2/ε-MnO2催化剂表现出卓越的性能和稳定性.
科学领域:
- 材料科学 材料科学 材料科学
- 电化学 电化学 电化学
- 催化剂是一种催化剂.
- 绿色能源 绿色能源
背景情况:
- 贵金属电催化剂对于高效的酸性水氧化至关重要,对于绿色能源生产至关重要.
- 传统的催化剂由于在不活跃的支上具有较大的贵金属颗粒大小,因此受到有限的内在活性和较低的原子效率的影响.
- 开发高活性和稳定的电催化剂对于推进能技术至关重要.
研究的目的:
- 为了合成和评估氧化 (IrO2) 纳米集群,支持不同阶段的氧化还原活性二氧化 (MnO2) 纳米基质.
- 调查MnO2相 (α, δ和 ε) 对IrO2纳米集群的电催化活性和稳定性的影响,以氧化酸性水.
- 阐明结构-活性关系,并了解金属支相互作用在增强催化性能中的作用.
主要方法:
- 在α-MnO2, δ-MnO2和 ε-MnO2纳米基板上支持的IrO2纳米集群 (<2 nm) 的合成.
- 电化学测量,包括在0.5M H2SO4中在10mA cm-2的超电位测定和长期稳定性测试.
- 射线光电子光谱 (XPS),巴德尔电荷分析和密度功能理论 (DFT) 计算来探测电子结构和金属支相互作用.
主要成果:
- 氧2/ε-MnO2表现出优异的氧演变反应 (OER) 性能,在10 mA cm-2时具有225 mV的低超电位,优于氧2/α-MnO2 (242 mV) 和氧2/δ-MnO2 (286 mV).
- 氧化2/ε-MnO2催化剂表现出强大的稳定性,在50小时的10 mA cm-2.2连续运行中保持其运行潜力.
- 发现IrO2/ε-MnO2中强烈的金属支相互作用调节了Ir位点的电子结构并稳定了纳米集群,增强了活性和耐用性.
结论:
- ε-MnO2阶段为支持IrO2纳米集群提供了最佳的氧化还原活性纳米基质,从而显著提高了酸性OER性能.
- 增强的催化活性和稳定性归因于强大的金属支相互作用,这些相互作用优化了Ir的电子特性,并改善了纳米集群的定.
- 这项工作突出了合理设计的贵金属纳米集群在氧化还原活性支上,以有效和稳定地生产绿色的潜力.
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