在SmMn2O5表面使用合作格子氧化还原剂进行稳定和活性氧化催化
Yongping Zheng1, Sampreetha Thampy1, Nickolas Ashburn1
1Department of Materials Science and Engineering , University of Texas at Dallas , Richardson , Texas 75080 , United States.
Journal of the American Chemical Society
|June 29, 2019
概括
研究人员通过在SmMn2O5聚氧化物中利用合作晶格氧氧还原剂来克服催化剂设计的挑战. 这种方法可以实现氧化反应的高热稳定性和催化活性.
科学领域:
- 材料科学
- 催化剂
- 表面化学
背景情况:
- 在恶劣条件下开发完整氧化反应的氧化催化剂受到格子氧结合能和氧化活性之间的反向相关性限制.
- 较强的氧结合确保了表面稳定性,但降低了催化活性,而较弱的结合增强了活性,但损害了稳定性.
研究的目的:
- 调查氧化催化剂中可否绕过晶格氧结合能和氧化活性之间的矛盾相关性.
- 探索合作晶格氧氧还原机制的潜力,以设计稳定和活跃的氧化催化剂.
主要方法:
- 使用氧化 (NO) 催化氧化作为研究氧化催化剂的模型反应.
- 使用现场光谱技术和理论计算 (隐含) 调查了SmMn2O5的表面反应机制.
主要成果:
- 证明SmMn2O5聚氧化物上的合作晶格氧化还原成功地避免了结合能和活性之间的典型权衡.
- 确定了一种反应途径,涉及桥接和单酸盐中间体,氧气空缺和合作晶格氧气参与.
- 展示了催化剂在苛刻条件下保持稳定和活跃的表面结构的能力.
结论:
- 合作晶格氧氧还原为克服设计氧化催化剂完全氧化的基本局限性提供了一种可行的策略.
- 这些发现为反应机制提供了关键的见解,使先进的氧化催化剂能够合理设计,具有增强的O2激活,高氧活性和卓越的热稳定性.
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