在CeO2或ZrO2基上支持Pd催化剂的催化性能为甲氧化改性β-热酸盐
Yingao Zhang1, Zidi Yan2, Min Xiao2
1School of Rare Earths, University of Science and Technology of China, Hefei 230026, China; Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou 341000, China.
Journal of environmental sciences (China)
|December 1, 2024
概括
与 (Ce-beta) 或无催化剂相比, (Zr-beta) 催化剂显著提高了甲氧化效率和稳定性. 这种增强源于更好的散和活性位形成,这对于甲燃烧催化剂至关重要.
科学领域:
- 催化剂是一种催化剂.
- 材料科学 材料科学 材料科学
- 环境化学环境化学
背景情况:
- 甲氧化对于能源生产和污染控制至关重要.
- 开发高效,稳定的甲燃烧催化剂是一个关键的挑战.
- 支持热的金属催化剂为催化应用提供可调节的特性.
研究的目的:
- 为了合成和评估支持Zr-β和Ce-β热石的基催化剂,用于甲氧化.
- 研究Zr和Ce兴奋剂对催化剂性能和稳定性的影响.
- 为了阐明这些复合催化剂中控制甲氧化的结构-活性关系.
主要方法:
- 湿浸方法用于制备氧化氧化复合体支 (Ce-β,Zr-β).
- 制备基于的催化剂 (Pd/Zr-β, Pd/Ce-β, Pd/β).
- 通过甲氧化试验对催化性能进行表征,包括T50和T90的确定.
- 动力分析以确定周转频率 (TOF).
- 分析催化剂结构和金属支相互作用.
主要成果:
- Pd/6.8Zr-β催化剂表现出优越的甲氧化性能,T50 = 417 °C和T90 = 451 °C,以及强大的热水稳定性.
- 与Pd/β催化剂相比,Zr的加入几乎使甲燃烧的周转频率 (TOF) 增加了三倍.
- 在Pd/8.6Ce-beta中,石孔内聚合的CeO2导致不活跃的Pd4+物种和降低的催化效率.
- 优化的Zr分散促进了活跃的PdO位点,并促进了氧气迁移,增强了活性和稳定性.
结论:
- 在β氧化物中使用的兴奋剂显著增强了催化剂的活性和稳定性,以氧化甲.
- 对于促进活跃的PdO位点和维持Pd2+含量而言,Zr在石表面的分散是至关重要的.
- 导致聚合和增强金属支相互作用的Ce兴奋剂对催化性能产生不利影响.
- 补充剂的选择和分散控制对于设计有效的甲氧化催化剂至关重要.
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