站点多样性和连接在电化学CO减排中的重要性
Chansol Kim1,2,3, Nitish Govindarajan4, Sydney Hemenway1,5
1Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
概括
在铜 (Cu) 上的电催化 CO2 减少显示,当较不活跃的地点储存 CO 时,乙烯生产得到改善. 这种二氧化碳储供应是催化剂性能的关键,而不仅仅是单独活跃的地点.
科学领域:
- 电化学 电化学 电化学
- 催化剂是一种催化剂.
- 材料科学 材料科学 材料科学
背景情况:
- 铜 (Cu) 的电化学二氧化碳减排是从可再生资源生产有价值化学品的有希望的途径.
- 在Cu催化剂制备中的变化导致单碳和多碳产品的活性和选择性不同.
研究的目的:
- 研究二氧化碳表面储库在Cu电催化剂上的电化学二氧化碳减少反应 (COR) 中的作用.
- 了解催化剂的制备和操作条件如何影响二氧化碳储动力学和乙烯选择性.
主要方法:
- 用气体扩散电极 (GDE) 电池调整化学瞬态动力学以电催化.
- 在Ar和CO之间突然切换料气,以测量动态反应和CO氧化 (COR) 延迟时间.
- 开发一个三位点微动力学模型,以捕捉动态行为和二氧化碳储特性.
主要成果:
- 较少活跃的二氧化碳储存点的较大部分增强了对乙烯的有效催化活性.
- 具有显著延迟时间的Cu催化剂表现出较不活跃的CO储库,并迅速扩散到活跃位点.
- 据估计,高达88%的氧化物衍生Cu (OD-Cu) 在-1.52V与SHE的CO储表面覆盖率与乙烯周转频率的增加相关.
结论:
- 通过二氧化碳储存所促进的向活性站点供应二氧化碳对于电化学COR中的C2+产品选择性至关重要,而不仅仅是单独的活性站点.
- 催化剂网络的多样性和站点间的运输途径是整体Cu电催化剂活动的关键因素.
- 未来的催化剂设计必须考虑不同催化场和二氧化碳转运之间的动态相互作用.
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