Construction of V₂O₅-WO₃/TiO₂ nanocones catalyst layer on SiC ceramic membrane for efficient removal of NO and dust

In this work, TiO₂ nanocones grown on SiC membrane was used as the support of V₂O₅-WO₃ species to prepare V₂O₅-WO₃/TiO₂@SiC (VWTi(C-X)@SiC) catalytic membrane for dust filtration and NH₃-SCR denitration. On account of the large specific surface area, abundant surface acid sites and prominent redox property, the optimized VWTi(C-550)@SiC catalytic membrane shows >90% NO removal efficiency at the temperature of 280–360 °C, which are much higher than VWTi(P-550)/SiC catalytic membrane (TiO₂ nanoparticles prepared by traditional vacuum coating titanium sol method was used as the support of V₂O₅-WO₃ species, NO conversion <80% at whole tested temperature). Additionally, VWTi(C-550)@SiC displays superior stability during the SO₂ + H₂O resistance and 300 h long-term test at 300 °C, and exhibits an excellent dust filtration performance (2.5 μm SiO₂ particles interception rate exceeded 99.99%) under all test conditions. More importantly, the structure of nanocones decrease the influence of tensile stresses due to the different thermal expansion coefficients of TiO₂ and SiC membranes, which significantly suppress the fall of VWTi catalyst layer from the surface of SiC during pulse-jet cleaning. Among above results, it can be concluded that the optimized VWTi(C-550)@SiC catalytic membrane shows a prosperous application prospect for the simultaneously dust filtration and NH₃-SCR denitration of medium–high temperature flue gas.