在氧化单壁碳纳米管上的高协调性分子-酸电催化剂,用于高效的过氧化生产
Yaoxin Li1,2, Haoying Cheng2,3, Meilin Wang2,3
1College of Chemistry, Fuzhou University, Fuzhou, Fujian 350108, China. xujx_1220@fjirsm.ac.cn.
Materials horizons
|March 18, 2024
概括
这项研究在氧化碳纳米管上引入了一种新的-酸催化剂,通过两电子氧降解反应 (2e-ORR) 通过高效的过氧化 (H2O2) 电合成. 催化剂在中性电解质中表现出高选择性和稳定性,为传统方法提供了更绿色的替代方案.
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:
- 双电子氧降解反应 (2e- ORR) 是H2O2生产的一个有前途的途径,它比人类方法提供了环境优势.
- 开发具有成本效益和高效率的电催化剂对于工业化ORR技术至关重要.
- 单原子催化剂 (SAC) 提供高原子利用效率和可调节的电子特性.
研究的目的:
- 为了合成和表征一种超分子催化剂 (在氧化单壁碳纳米管上的-酸,CoPc/o-SWCNT) 进行高效的2e-ORR驱动的H电合成.
- 为了研究结构-活性关系和氧功能组在催化剂性能上的作用.
- 为了评估催化剂在中性电解质中的性能,使用H细胞和流细胞配置.
主要方法:
- 溶液自组合方法用于合成CoPc/o-SWCNT超分子催化剂.
- 结构特征 (例如,TEM,XPS) 和密度功能理论 (DFT) 计算以阐明催化剂结构和电子特性.
- 在H细胞和流细胞组合中进行电化学测量,以评估H2O2生产,选择性和稳定性.
主要成果:
- CoPc/o-SWCNT催化剂表现出调整的CO氧化状态,这是由于o-SWCNTs与氧功能组的相互作用,形成了两个额外的Co-O键.
- DFT计算显示,由桥接氧原子调节的Co位点的压缩d波段中心优化了氧中间体 (*OOH) 的结合,有利于2e-ORR.
- 优化的催化剂 (CoPc-6wt% / o-SWCNT-2) 在中性电解质中表现出色:高H2O2生成,选择性 (∼83-95%) 和稳定性 (H细胞中75小时).
- 在流电池装置中,催化剂实现了高电流密度 (45 mA cm-2),周转频率 (25.3 ± 0.5 s-1) 和生产率 (5.85 mol g-1 h-1) 的 1.2 wt% 连续 H2O2积累.
结论:
- 超分子CoPc/o-SWCNT催化剂在中性介质中有效地催化了2e-ORR用于H电合成.
- 增强的分子间相互作用和单原子Co位点的优化电子结构是实现高性能的关键.
- 这种催化剂代表了与现有的非贵金属SAC相比,在中性选择性H2O2生产方面取得的重大进展.
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