Chlorine poisoning-resistant atomically dispersed Ru for low-temperature o-dichlorobenzene oxidation

The performance of pure MnOx in efficient oxidation of polychlorinated aromatic hydrocarbons (PCAHs) are hindered by the poor resistance to chlorine poison, for which the addition of Ru can overcome. Nevertheless, the current research predominately focused on Ru particles, motivated by the inherent economic advantages of atomically dispersed sites, we have expanded the field to cover Ru single atom catalyst (SAC) supported by MnOx. With Ru loading of only 0.2 wt%, 0.2 Ru1/MnOx SAC exhibited superior low-temperature activity (T50 = 157.8 degrees C, T90 = 180.5 degrees C vs T50 = 163.3 degrees C, T90 = 198.1 degrees C under WHSV of 36000 cm3 g-1 & sdot;h- 1) and chlorine poisoning resistance, with conversion stable at 90 % over 700 min compared to a 30 % drop within 100 min, comparing with pure MnOx. X-ray photoelectron spectroscopy, H2 temperature-programmed reduction and theoretical calculation demonstrate that the superior chlorine poisoning resistance of Ru1/MnOx SAC originates from not only the role of Ru in enabling the Deacon reaction for chloride species removal, but also its role in preventing the MnOx support structure from on-stream sintering through the support-metal interaction, which provides Ru1/MnOx SAC more negative adsorption energy and lower C-Cl bond broken energy barrier during PCAHs destruction relative to other noble metal-based systems. The present work deepens the understanding on designing atomically dispersed Ru catalysts and their application potential for environmental pollutants.