SO 2 - and H 2 O-Tolerant Catalytic Reduction of NO x at a Low Temperature via Engineering Polymeric VO x Species by CeO 2 .

Selective catalytic reduction (SCR) of NO x over V 2 O 5 -based oxide catalysts has been widely used, but it is still a challenge to efficiently reduce NO x at low temperatures under SO 2 and H 2 O co-existence. Herein, SO 2 - and H 2 O-tolerant catalytic reduction of NO x at a low temperature has been originally demonstrated via engineering polymeric VO x species by CeO 2 . The polymeric VO x species were tactfully engineered on Ce-V 2 O 5 composite active sites via the surface occupation effect of Ce, and the obtained catalysts exhibited remarkable low-temperature activity and strong SO 2 and H 2 O 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 4 + /NH 3 species and gaseous NO. In the presence of SO 2 and H 2 O, the polymeric VO x species had not been hardly influenced, while the formation of sulfate species on Ce sites not only promoted the adsorption of NH 4 + species and the reaction between gaseous NO and NH 4 + but also facilitated the decomposition of ammonium bisulfate through weakening the strong bond between HSO 4 - and NH 4 + . This work provided a new strategy for SO 2 - and H 2 O-tolerant catalytic reduction of NO x at a low temperature.