电化学培养的铜纳米集群的尺寸依赖性,这些纳米集群来自单个铜原子,用于减少CO的反应
Keitaro Ohashi1, Kosei Nishimura1, Kaito Nagita1
1Research Center for Solar Energy Chemistry, Graduate School of Engineering Science, Osaka University, Toyonaka, 560-8531, Osaka, Japan.
ChemSusChem
|January 24, 2025
概括
较小的铜纳米集群 (CuNCs) 在CO还原反应中增强了多碳的产生. 具有更高表面协调数的大型CuNC有利于CO二分化,提高了电催化中的C2+选择性.
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.
背景情况:
- 单原子催化剂可以合成超小的铜纳米集群 (CuNCs,<3nm).
- 与较大的Cu纳米粒子 (>10 nm) 相比,CuNCs在CO2和CO减少反应 (CO2RR/CORR) 中表现出明显的产品选择性.
研究的目的:
- 在CORR中研究电化学培养的CuNCs对于多碳 (C2+) 生产的尺寸依赖性选择性.
- 了解CuNC大小,表面结构和催化性能之间的关系.
主要方法:
- 电化学合成CuNCs从单个Cu原子在共价三酶框架 (Cu-CTFs) 上.
- 操作X射线吸收细结构 (XAFS) 分析以表征CuNCs.
- 密度函数理论 (DFT) 计算以建模反应机制和中间体.
主要成果:
- 具有不同Cu负载的Cu-CTF (1.21 wt%和0.41 wt%) 分别产生了2.0nm和1.1nm的CuNC.
- 更高的Cu负载 (Cu(h) -CTFs) 导致更大的CuNCs (2.0 nm) 和显著更高的C2+选择性 (52.3%的法拉第效率) 在-1.0V与RHE.
- CuNC的大小与表面协调号 (SCN) 相相关;较大的群体具有更多的SCN 8或9位点.
- DFT的计算表明,由于*OCCO中间体的稳定性,CO二分化在SCN 8或9处更受欢迎.
结论:
- 在CORR中的电催化性能强烈依赖于CuNC的大小.
- 较大的CuNC,具有更高的SCN,促进CO二极化并增强C2+生产.
- 这项研究提供了设计高效的电催化剂的见解,通过控制纳米集群大小和表面结构来减少二氧化碳.
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