在Pt/SSZ-13上,H2O和CO2对CO氧化的作用,其活性位点由易斯酸度调节
Yunhe Li1, Yanming Ma1, Yilin Wei2
1Marine Engineering College, Dalian Maritime University, Dalian 116026, China.
The Journal of chemical physics
|December 20, 2024
概括
水通过改变活性部位和减轻二氧化碳 (CO2) 抑制来增强碳一氧化物 (CO) 氧化,而不是以酸盐催化剂. 易斯酸度调节是优化工业应用中催化剂性能的关键.
科学领域:
- 不同质的催化剂.
- 热带石的化学结构
- 表面科学是一门科学.
背景情况:
- 控制石中的金属颗粒大小对于催化活性至关重要.
- 水和二氧化碳对以热为基础的金属催化剂的影响尚不清楚.
- 了解这些影响对于工业应用,如CO氧化,至关重要.
研究的目的:
- 为了研究水 (H2O) 和二氧化碳 (CO2) 对CO氧化的影响.
- 探索易斯酸度在控制热酸催化剂活性位点中的作用.
- 阐明Pt/SSZ-13上涉及H2O和CO2的反应机制.
主要方法:
- 使用不同SiO2/Al2O3比率的Pt/SSZ-13催化剂.
- 在现场采用分散反射率红外里埃变换光谱 (DRIFTS).
- 进行了H218O同位素标记实验,用于机械学研究.
主要成果:
- 水增强了CO的氧化,减少了CO2的抑制.
- 低SiO2/Al2O3比率促进Pt分散,高的Ptn+/Pt比率,以及小的Pt颗粒.
- 二氧化碳抑制了CO吸附;水削弱了Pt-CO键,并参与了氧物种的形成.
结论:
- 水通过修改活性点和反应路径,在促进CO氧化方面发挥着至关重要的作用.
- 易斯酸度是控制金属分散和氧化状态的关键因素,影响催化活性.
- 这些发现为优化在存在H2O和CO2的情况下对CO氧化氧化基催化剂的优化提供了洞察力.
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