International Joint Laboratory of Catalytic Chemistry, State Key Laboratory of Advanced Special Steel, Department of Chemistry, Research Center of Nano Science and Technology, College of Sciences, Shanghai University, Shanghai 200444, P. R. China.
Environ Sci Technol. 2022 Mar 15;56(6):3719-3728. doi: 10.1021/acs.est.1c08009. Epub 2022 Feb 28.
The synergistic catalytic removal of NO and chlorinated volatile organic compounds under low temperatures is still a big challenge. Generally, degradation of chlorinated organics demands sufficient redox ability, which leads to low N selectivity in the selective catalytic reduction of NO by NH (NH-SCR). Herein, mediating acid sites introducing the CePO component into MnO/TiO NH-SCR catalysts was found to be an effective approach for promoting chlorobenzene degradation. The observation of diffuse reflectance infrared Fourier transform ( DRIFT) and Raman spectra reflected that the Lewis acid sites over CePO promoted the nucleophilic substitution process of chlorobenzene over MnO by weakening the bond between Cl and benzene ring. Meanwhile, MnO provided adequate Brønsted acid sites and redox sites. Under the cooperation of Lewis and Brønsted acid sites, relying on the rational redox ability, chlorobenzene degradation was promoted with synergistically improved NH-SCR activity and selectivity. This work offers a distinct pathway for promoting the combination of chlorobenzene catalytic oxidation and NH-SCR, and is expected to provide a novel strategy for synergistic catalytic elimination of NO and chlorinated volatile organic compounds.
低温下协同催化去除 NO 和含氯挥发性有机化合物仍然是一个巨大的挑战。通常，含氯有机物的降解需要足够的氧化还原能力，这导致了 NH-SCR 中 NO 选择性还原的 N 选择性较低。在此，将 CePO 成分引入 MnO/TiO2 NH-SCR 催化剂中，发现介体酸位是促进氯苯降解的有效方法。漫反射红外傅里叶变换（DRIFT）和拉曼光谱的观察表明，CePO 上的路易斯酸位通过削弱 Cl 与苯环之间的键，促进了氯苯在 MnO 上的亲核取代过程。同时，MnO 提供了足够的 Brønsted 酸位和氧化还原位。在路易斯酸位和 Brønsted 酸位的协同作用下，依靠合理的氧化还原能力，促进了氯苯的降解，同时协同提高了 NH-SCR 的活性和选择性。这项工作为促进氯苯催化氧化和 NH-SCR 的结合提供了一条明显的途径，有望为协同催化消除 NO 和含氯挥发性有机化合物提供一种新的策略。
