A strategy for constructing highly efficient Co₃O₄-C@SiO₂ nanofibers catalytic membrane for NH₃-SCR of NO and dust filtration

The strategy of constructing catalytic membrane has a significant influence on its structure and performance. In this work, Co₃O₄-C_x@SiO₂ nanofiber membranes (NFMs) were fabricated by an in-situ growth–pyrolysis–oxidation strategy. The Co₃O₄-C_x catalyst derived from ZIF-67 was wrapped around nanofibers, which helps to maintain a stable membrane structure, then suppressing the reduction of gas permeability. Among the Co₃O₄-C_x catalyst, the carbon skeleton can prevent the agglomeration of Co₃O₄ nanoparticles, obtaining an ultra-fine Co₃O₄ nanoparticles with high dispersibility, redox property and surface area. The obtained Co₃O₄-C₃₀₀@SiO₂ NFM exhibits outstanding ammonia selective catalytic reduction (NH₃-SCR) denitrification activity (T₉₀ = 225 °C at a GHSV of 77,000 h⁻¹). The effect of catalyst loading on PM_2.5 filtration performance of SiO₂ NFM was also tested. Co₃O₄-C₃₀₀@SiO₂ NFM has higher filtration efficiency (99.99%) than SiO₂ NFM at a lower pressure drop of 58 Pa, which suggests that catalyst loading via our method can improve the filtration performance of SiO₂ NFM. This work might provide a universal strategy for the design and preparation of highly efficient catalytic membrane.