基于Mn-mullite (Sm,Gd) 的混合相氧化物催化剂Mn2O5用于柴油废气中NO氧化
Weichao Wang1, Geoffrey McCool, Neeti Kapur
1Nanostellar Inc., 3696 Haven Avenue, Redwood City, CA 94063, USA. wwang@nanostellar.com
Science (New York, N.Y.)
|August 21, 2012
概括
研究人员开发了一种基于的新型混合相氧化物催化剂,可以有效氧化柴油废气中的氧化 (NO). 这种具有成本效益的材料在活性和耐久性方面优于催化剂,为排放控制提供了一个有希望的替代品.
科学领域:
- 材料科学 材料科学 材料科学
- 催化剂是一种催化剂.
- 环境工程 环境工程
背景情况:
- 选择性催化减排 (SCR) 和性NOx捕获 (LNT) 装置对于柴油发动机排放控制至关重要.
- 目前使用 (Pt) 基催化剂,但由于高成本和NO氧化效率有限而受到影响.
- 开发具有成本效益和高活性的NO氧化催化剂仍然是一个重大挑战.
研究的目的:
- 研究基于Mn-mullite (Sm,Gd) 的混合相氧化物材料Mn(2) O(5) 作为Pt基催化剂的有效替代品.
- 在模拟的柴油废气条件下评估开发的氧化物材料的催化活性,成本和热耐用性.
- 用计算和光谱技术阐明NO氧化机制.
主要方法:
- 混合相Mn-mullite氧化物材料的合成和表征.
- 在实验室模拟的柴油废气条件下测试催化性能.
- 利用密度函数理论 (DFT) 和扩散反射率红外里埃变换光谱 (DRIFTS) 进行机械学研究.
主要成果:
- 与NO氧化中的Pt催化剂相比,Mn-mullite氧化物材料表现出优异的性能.
- 氧化物材料在较低的温度下 (从120°C开始) 呈现出更高的催化活性,转化最大值明显更高.
- 这种材料比基于Pt的催化剂具有更高的成本效益和热耐用性.
- DFT和DRIFTS研究揭示了涉及Mn-Mn活性位点和中间酸盐物种的反应机制.
结论:
- 混合相Mn-mullite氧化物是Pt催化剂的高效和经济有效的替代品,用于柴油废气中NO氧化.
- 这些材料提供了更好的催化活性和热稳定性,解决了当前技术的主要局限性.
- 机械学的洞察力为设计下一代催化剂的NOx减排系统提供了基础.
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