Synthesis and Characterization of Electrospun Nanofibers of Sr-La-Ce Oxides as Catalysts for the Oxidative Coupling of Methane

Catalytic nanofibers composed of La-Ce and Sr-La-Ce oxides were synthesized by the electrospinning method with 5 wt % Sr and different La/Ce molar ratios. The materials were obtained by calcining electrospun polymer composite fibers and were studied for the oxidative coupling of methane. The catalytic performance was compared with analogous Sr-La-Ce powder catalysts. SEM micrographs of Sr-La-Ce fibers (La/Ce: 0.1, 0.2, 1, and 3) showed nanostructures with homogeneous and uniform diameters (170–200 nm). In addition, the XRD patterns revealed the formation of crystalline solid solutions like La_xCe_yO_z. The strontium enhanced the CH₄ conversion and C₂ selectivity since it possibly generated structural defects that promote the formation of superoxide species. The SrLaCe3 nanofibers reached a CH₄ conversion of 28.5% and C₂ yield of 21.7% at 600 °C. The randomly packed nanofibers improved the heat and mass transfer properties due to their high geometric surface ratio with high bed porosity.