Effect of processing route on the properties of Ni-based catalytic filters obtained from natural amorphous silica fibers

In this work catalytic fibrous filters were produced through two distinct processing routes from natural amorphous silica fibers (NASF) and Ni(NO3)2 solution (wet route) and NiO (dry route) as catalyst precursors. The Ni–SiO2 fibers were characterized for X-ray powder diffraction, scanning electron microscope, particle size distribution, specific surface area, nickel contents, porosity, tortuosity, permeability, compressive strength, degree of dispersion, filtration and gas conversion efficiency. Morphological characterization revealed that Ni from wet route was distributed over the silica fibers with significantly lower particle size than the Ni produced through the dry route. Both methods led to a homogeneous distribution of Ni. The catalytic fibrous filter obtained from the dry route showed higher conversion efficiency for both propylene and propane, especially at high temperatures, due to the higher degree of dispersion of Ni particles over the NASF surfaces.