在乙烯化中解开硫合金金背后的复杂因果关系
Yifei Zhang1, Xinrui Gu2, Zhiwen Li2
1Institute of Catalysis for Energy and Environment, College of Chemistry and Chemical Engineering, Shenyang Normal University, Shenyang 110034, China.
在AC-300催化剂上的金纳米集群 (Au25) 在乙烯化中表现出色,实现高乙烯单体选择性. 黄金集群上的硫种增强了催化稳定性和活性.
科学领域:
- 材料科学 材料科学 材料科学
- 催化剂是一种催化剂.
- 纳米技术 纳米技术
背景情况:
- 乙烯基化物单体 (VCM) 是聚乙烯基化物 (PVC) 塑料的关键组成部分.
- 高效和选择性的催化过程对于VCM生产至关重要.
- 金纳米集群正在成为各种化学转换的有希望的催化剂.
研究的目的:
- 开发高活性和选择性的黄金基催化剂,用于乙烯化.
- 调查催化剂预处理和表面物种在催化性能中的作用.
- 了解黄金催化乙烯化的机制.
主要方法:
- 在不同温度 (300°C和500°C) 上预处理的金纳米集/活性碳 (Au25/AC) 复合材料的合成和表征.
- 在特定条件下测试乙烯化反应 (180°C,36mLg-1h-1).
- 描述技术包括传输电子显微镜 (TEM),X射线光电子谱学 (XPS),温度编程的降低 (H2-TPR) 和现场紫外线光解离 (UPD).
主要成果:
- Au25/AC-300复合材料表现出卓越的催化性能,具有>94%的乙烯转化率和>99%的乙烯化物选择性.
- 具有较大的金纳米颗粒的Au25/AC-500,表现出较低的催化活性.
- 在Au25/AC-300表面的残留硫种被确定为抑制黄金减少和聚合的关键,保持催化活性.
结论:
- 由硫种稳定的Au25/AC-300催化剂在乙烯化中提供了卓越的性能.
- 硫种在保持黄金纳米集群的完整性和活动方面发挥着至关重要的作用.
- [Au25S]+集群和乙分子之间的强烈相互作用是增强催化过程的关键.
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