Large-scale growth of hierarchical transition-metal vanadate nanosheets on metal meshes as monolith catalysts for De-NOx reaction

Abstract

A facile method is developed for the large-scale growth of hierarchical transition-metal (Cu, Fe, and Ni) vanadate nanosheets on corresponding metal mesh as supports. The hierarchical transition-metal vanadate nanosheets were in situ grown on the metal meshes through an orientational etching process and simultaneous nucleation and growth process. Interestingly, the morphologies of the vanadate nanosheets are governed by the balance between dissolution rate and nucleation rate. Thus, the sizes and the thicknesses of the nanosheets could be facilely controlled by the reaction duration, the acidity of the solution and the concentration of vanadate precursor. Furthermore, the hierarchical transition-metal vanadate nanosheets supported on metal meshes are used as monolith catalysts for the selective catalytic reduction (SCR) of NO with NH₃. The iron mesh based monolith catalyst shows excellent de-NO_x performance with high efficiency and stability in the presence of SO₂ and H₂O, which provide a promising monolith de-NO_x catalyst for stationary source at medium temperatures.