在Palladium-Gold合金中的间歇性碳补充剂提高了乙烯基单体合成中的催化性能
在PubMed上查看摘要
概括
此摘要是机器生成的。我们发现地下碳通过增强Pd-Au催化剂来增强乙烯基单体 (VAM) 合成. 增加了碳化物分量,显著提高了VAM形成率和选择性.
科学领域
- 不同质的催化
- 材料科学
- 化学工程
背景情况
- 乙单体 (VAM) 是一个重要的工业化学物质.
- 目前的VAM合成依赖于使用Pd-Au/SiO2催化剂和KOAc促进剂的乙烯乙氧化.
- 黄金 (Au) 和酸盐 (KOAc) 的确切作用尚不清楚.
研究的目的
- 阐明地下碳,Au和KOAc在VAM合成中的作用.
- 了解增强催化性能背后的机制.
- 解决关于催化剂功能的长期争论.
主要方法
- 对X射线衍射 (XRD) 和X射线吸收细结构 (XAFS) 的研究.
- 动力和理论分析.
- 在工艺条件下对催化剂性能进行评估.
主要成果
- 碳原子自发地入Pd-Au合金网格,形成地表碳.
- 加入KOAc显著增加了平衡碳化物分量.
- 与Pd-Au/SiO2相比,KOAc/Pd-Au/SiO2的催化剂具有5.6倍的VAM形成率和89.0%的选择性 (69.2%的选择性).
- 和间碳的协同作用增强了乙酸和乙烯的速率决定性合,同时抑制了二氧化碳的形成.
结论
- 在VAM合成中,地表碳充当催化剂.
- KOAc促进碳化物形成,对于高催化活性至关重要.
- 这项研究阐明了Au和KOAc的作用,使得可以合理设计催化剂以改善VAM生产.
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