用弱稳定剂合成的2nm直径催化活性金纳米颗粒的尺寸稳定性研究
Dhruba K Pattadar1, Francis P Zamborini1
1Department of Chemistry , University of Louisville , Louisville , Kentucky 40292 , United States.
Journal of the American Chemical Society
|October 5, 2018
概括
小金纳米粒子 (Au NPs) 对电催化有希望,但其尺寸稳定性不佳. 它们在各种条件下溶解或聚合的倾向限制了它们的实际应用.
科学领域:
- 纳米材料科学
- 电化学
- 催化剂
背景情况:
- 2nm以下的金纳米粒子 (AuNP) 具有独特的催化性能.
- 稳定剂在纳米粒子大小和稳定性方面起着至关重要的作用.
- 了解NP稳定性是开发高效电催化剂的关键.
研究的目的:
- 与较大的酸盐稳定 Au NPs (Cit Au NPs) 相比,研究了酸盐稳定 Au 纳米粒子 (THPC Au NPs) 的尺寸稳定性.
- 评估电化学条件,化物和臭氧对NP尺寸稳定性的影响.
- 评估THPC Au NP的电催化活性,以减少二氧化碳和转化.
主要方法:
- 1.5-2.0 nm THPC Au NPs和4 nm Cit Au NPs的合成和表征
- 阳极剥离电压测量以评估氧化溶解潜力.
- 在酸电解质中进行电化学循环,以研究表面氧化物形成和减少.
- 暴露于化物和臭氧以诱导奥斯瓦德成熟和聚合.
- 在不同条件下对NP大小的变化进行比较分析.
主要成果:
- 与Cit Au NPs和散装黄金相比,THPC Au NPs具有显著较低的氧化溶解潜力.
- 在酸电解质中的单次电化学循环导致THPC Au NPs从2nm增加到4nm.
- 在化物存在的情况下,THPC Au NP经历奥斯瓦尔德成熟,并在暴露于臭氧时聚合,从而增加NP大小.
- 与Cit Au NPs相比,THPC Au NPs在减少二氧化碳和转化方面表现出更强的电催化活性.
- 在所有测试条件下,Cit Au NP表现出优异的尺寸稳定性.
结论:
- 具有THPC等弱稳定剂的2nm以下AuNP具有高度反应性,但其尺寸稳定性较差.
- 氧化溶解,奥斯瓦尔德成熟和聚合是小型Au NP电催化剂面临的重大挑战.
- 取决于尺寸的特性和稳定剂的选择对电化学应用中的NP反应性和稳定性具有关键影响.
- 需要进行进一步的研究,以开发用于催化中的小型AUNP的强大稳定策略.
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