Cu2O纳米立方体在酸盐电还原到氨中的结构和组成变化的作用
Igor Messias1, Manuel E G Winkler1,2, Gabriel F Costa1,3
1Institute of Chemistry, University of Campinas, Campinas, SP 13083-862, Brazil.
ACS applied energy materials
|October 18, 2024
概括
这项研究表明,氧化铜纳米立方体在酸盐电还原过程中转化为铜,形成活性表面,增强氨生产. 这种动态转变是提高催化剂性能和稳定性的关键.
科学领域:
- 电化学 电化学 电化学
- 材料科学 材料科学 材料科学
- 催化剂是一种催化剂.
背景情况:
- 酸盐电还原反应 (NO3RR) 到氨 (NH3) 对于可持续的固定至关重要,但在催化剂活性和稳定性方面面临挑战.
- 基于铜的催化剂对NO3RR有希望,但它们的结构演变和性能之间的关系尚未完全理解.
研究的目的:
- 为了研究在性电解质中NO3RR期间Cu2O纳米立方体的动态变化.
- 为了将催化剂的结构和化学变化与氨生产效率和稳定性相关联.
主要方法:
- 在NO3RR期间,使用电子显微镜,Raman,XRD和XANES在NO3RR期间对Cu2O纳米立方体的系统监测.
- 电化学分析包括静电电解和现场FTIR和DEMS,以探测中间体和副产品.
主要成果:
- 最大NH3法拉代效率 (94%) 和产率 (149μmol h-1 cm-2) 在1小时内在0.3V与RHE之间实现.
- 在 -0.20 V 和 RHE 的长期电解显示,在 10 小时内,NH3 法拉代克效率从 73% 增加到 ~ 90%.
- Cu2O纳米立方体转化为氧化物衍生Cu0 (OD-Cu),剩下的Cu2O相,表明复杂的活性表面演变.
结论:
- 在NO3RR中Cu2O纳米立方体的高活性和选择性归因于OD-Cu丰富表面的动态形成,而不仅仅是最初的结构.
- 演变的表面,从近表面到底层,在反应机制中起着关键作用.
- 了解这些动态转换对于设计稳定高效的氨合成电催化剂至关重要.
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