National Engineering Laboratory for VOCs Pollution Control Material & Technology, Research Center for Environmental Material and Pollution Control Technology, University of Chinese Academy of Sciences, Beijing 101408, P.R. China.
Environ Sci Technol. 2024 Jan 30;58(4):2153-2161. doi: 10.1021/acs.est.3c09741. Epub 2024 Jan 20.
Nitrous oxide (NO) has a detrimental impact on the greenhouse effect, and its efficient catalytic decomposition at low temperatures remains challenging. Herein, the cobalt-based high-entropy oxide with a spinel-type structure (Co-HEO) is successfully fabricated via a facile coprecipitation method for NO catalytic decomposition. The obtained Co-HEO catalyst displays more remarkable catalytic performance and higher thermal stability compared with single and binary Co-based oxides, as the temperature of 90% NO decomposition () is 356 °C. A series of characterization results reveal that the synergistic effect of multiple elements enhances the reducibility and augments oxygen vacancy in the high-entropy system, thus boosting the activity of the Co-HEO catalyst. Moreover, density functional theory (DFT) calculations and the temperature-programmed surface reaction (TPSR) with isotope labeling demonstrate that NO decomposition on the Co-HEO catalyst follows the Langmuir-Hinshelwood (L-H) mechanism with the promotion of abundant oxygen vacancies. This work provides a fundamental understanding of the synergistic catalytic effect in NO decomposition and paves the way for the novel environmental catalytic applications of HEO.
一氧化二氮(NO)对温室效应有不利影响,其在低温下的高效催化分解仍然具有挑战性。在此,通过简便的共沉淀法成功制备了具有尖晶石型结构的钴基高熵氧化物(Co-HEO),用于 NO 催化分解。与单一组分和双组分的 Co 基氧化物相比,所获得的 Co-HEO 催化剂表现出更优异的催化性能和更高的热稳定性,90%NO 分解的温度()为 356°C。一系列的表征结果表明,多种元素的协同效应增强了高熵体系中的还原性并增加了氧空位,从而提高了 Co-HEO 催化剂的活性。此外,密度泛函理论(DFT)计算和同位素标记的程序升温表面反应(TPSR)表明,Co-HEO 催化剂上的 NO 分解遵循 Langmuir-Hinshelwood(L-H)机制,丰富的氧空位对其具有促进作用。这项工作为深入了解 NO 分解中的协同催化效应提供了基础,并为 HEO 在新型环境催化应用方面开辟了道路。