用WO对Pt催化剂表面的动态和偏好的装饰对氧化反应的影响
Justin Marlowe1, Siddharth Deshpande2,3, Dionisios G Vlachos2,3
1Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, California 93106, United States.
Journal of the American Chemical Society
|May 13, 2024
概括
减少的氧化物 (WOx) 通过装饰 (Pt) 纳米颗粒来选择性地增强生物质的氧化 (HDO). 这种装饰阻断了不必要的芳香化,提高了HDO反应中的芳香产品选择性.
科学领域:
- 不同质的催化
- 材料科学
- 生物质利用
背景情况:
- 具有可降解过渡金属氧化物 (例如WOx,NbOx,TiO2) 的基催化剂在氧化 (HDO) 中对芳香产品具有很高的选择性.
- 这种选择性与金属催化剂观察到的典型芳香化形成鲜明对比,但底层活性位点仍然不清楚.
- 了解金属支相互作用对于控制生物质转化中的催化性能至关重要.
研究的目的:
- 使用可降解过渡金属氧化物装饰的Pt纳米颗粒来阐明HDO反应中高选择性的活性位点.
- 研究Pt表面的减少氧化 (WOx) 域的组织和优选装饰.
- 将理论预测与实验观测和催化性能相关联.
主要方法:
- 使用SurfGraph算法生成密度函数理论 (DFT) 对Pt表面的WOx剪切器的模型结构.
- 使用DFT数据训练的机器学习模型来识别优选的WOx职位和稳定性因素.
- 合成了WOx/Pt/SiO2催化剂,并使用光谱和显微镜进行了它们的特征测定,随后在HDO中对二素进行了催化测试.
主要成果:
- 理论模型预测和实验性表征证实了减少的WOx物种对协调良好的Pt位点 (≥8Pt协调数) 的偏好装饰.
- 发现WOx装饰通过阻断这些特定的Pt位点来抑制芳香环化.
- 催化剂合成和反应性测试验证了关于WOx负荷及其对HDO选择性的理论预测.
结论:
- 通过WOx对特定的Pt位点进行偏好的装饰是实现HDO反应高选择性的关键.
- 这种位点阻断机制抑制了不必要的副作用,提高了生物质中有价值的芳香产品的产量.
- 这些发现为设计和控制生物质价值化异质催化物的金属支相互作用提供了新的范式.
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