SO- and HO-Tolerant Catalytic Reduction of NO at a Low Temperature via Engineering Polymeric VO Species by CeO.

Selective catalytic reduction (SCR) of NO over VO-based oxide catalysts has been widely used, but it is still a challenge to efficiently reduce NO at low temperatures under SO and HO co-existence. Herein, SO- and HO-tolerant catalytic reduction of NO at a low temperature has been originally demonstrated via engineering polymeric VO species by CeO. The polymeric VO species were tactfully engineered on Ce-VO composite active sites via the surface occupation effect of Ce, and the obtained catalysts exhibited remarkable low-temperature activity and strong SO and HO tolerance at 250 °C. The strong interaction between Ce and V species induced the electron transfer from V to Ce and tuned the SCR reaction via the E-R pathway between the NH/NH species and gaseous NO. In the presence of SO and HO, the polymeric VO species had not been hardly influenced, while the formation of sulfate species on Ce sites not only promoted the adsorption of NH species and the reaction between gaseous NO and NH but also facilitated the decomposition of ammonium bisulfate through weakening the strong bond between HSO and NH. This work provided a new strategy for SO- and HO-tolerant catalytic reduction of NO at a low temperature.