低电子负性的Mn-PtMn纳米 dendrites的收缩增强氧降低耐久性
Yan Nie1,2, Yingjun Sun1, Bingyi Song3
1School of Materials Science and Engineering, Peking University, Beijing, 100871, China.
Angewandte Chemie (International ed. in English)
|December 28, 2023
概括
新的- (PtMn) 纳米烯酸催化剂提高了燃料电池中氧降解反应 (ORR) 的耐用性. 与传统-合金相比,这些催化剂显示出更好的稳定性和活性,减少金属在酸性条件下溶解.
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.
背景情况:
- 金属 (PtM) 合金是有效的氧降解反应 (ORR) 催化剂,但由于金属溶解,在酸性燃料电池环境中缺乏耐用性.
- 传统PtM催化剂中合金金属 (例如Ni) 的高电子负性有助于它们的降解.
研究的目的:
- 开发一种新的 - (PtMn) 合金纳米矿催化剂,提高ORR耐用性.
- 研究低电子负性的Mn收缩对PtMn合金稳定性和活性的影响.
- 为了比较PtMn催化剂与传统PtNi合金的性能和耐用性.
主要方法:
- 合成 PtMn 合金纳米.
- 电化学描述ORR活动和耐久性.
- 密度函数理论 (DFT) 计算用于热力学稳定性分析.
- 在氧燃料电池中制造和测试膜电极组件 (MEAs).
主要成果:
- 由于中等的应变,PtMn纳米 dendrites 显示出最佳的ORR活性 (0.53A/mg 在0.9V与RHE).
- PtMn催化剂在10,000个循环后显示出明显较少的过渡金属溶解和96%的质量活性保留,性能优于PtNi合金.
- DFT计算证实了PtMn比PtNi合金具有更高的热力学稳定性.
- PtMn MEAs在低Pt负载下达到1.36W/cm2的峰值功率密度,并在50小时内保持性能.
结论:
- PtMn合金纳米树脂为改善燃料电池中ORR耐用性提供了一个有希望的解决方案.
- 低电子阴性和的收缩效应增强了催化剂的稳定性,减少了降解.
- 这些发现为更强大,更高效的燃料电池技术铺平了道路.
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