催化作用
石墨烯
氧化物
材料科学
X射线光电子能谱
漫反射红外傅里叶变换
吸附
热脱附光谱法
X射线吸收精细结构
拉曼光谱
化学工程
解吸
纳米技术
无机化学
光催化
化学
光谱学
物理化学
冶金
生物化学
光学
量子力学
工程类
物理
作者
Yan Wang,Tong Shi,Qiyuan Fan,Yang Liu,Aiai Zhang,Zhaoqiang Li,Yanheng Hao,Lin Chen,Fenrong Liu,Xiaojun Gu,Shanghong Zeng
标识
DOI:10.1021/acscatal.2c01364
摘要
Tricomponent cerium–tungsten–titanium catalysts have the potential for selective catalytic reduction of NO by NH3, while the accurate modulating of the surface structure and the understanding of the atomic-level mechanism remain extremely challenging. To resolve the conundrum, here, we investigate the modular ternary catalysts through advanced spectroscopic and computational studies. It reveals that the introduction of graphene oxide induces a high dispersion of W and Ce species, resulting in the generation of amorphous W–O–Ce- and Ce–O–Ti-bonding structures on the surface. More importantly, the high dispersion of CeO2 facilitates the formation of abundant oxygen vacancies, which are mobile active sites for adsorption and activation of NO and NH3. Temperature-programmed desorption of NO (NO-TPD) and temperature-programmed desorption of NH3 (NH3-TPD) validate the feasibility of adsorption of NO and NH3 at low temperatures. In situ diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy of the transient reaction indicates that both NO2 and monodentate nitrate are active intermediates, which can react with the adsorbed NH3 to generate N2 and H2O during catalysis. X-ray absorption fine structure (XAFS), in situ Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS) provide direct evidence for the presence of Ce, W, and Ti interactions. Theoretical simulations prove that the inherent interactions reliably accelerate the conversion efficiency of NOx to N2 by improving the electron transfer on the surface. Furthermore, the Langmuir–Hinshelwood mechanism is thermodynamically more feasible and predominant over the graphene oxide-triggered catalyst.
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