The preferable Ni quantity to boost the performance of FSA for dry reforming of methane

Abstract

The spherical mesoporous Ni/fibrous silica-alumina (Ni/FSA) catalysts with varied Ni loadings (5–15 wt%) were effectively synthesized via hydrothermal method followed by impregnation method and catalytically evaluated through employing dry methane reforming. The XRD and FESEM mapping assessment demonstrated that the FSA has structural robustness independent of Ni loading quantities, and the NiO nanocrystalline size relies on the quantity of Ni loading. The mapping of FESEM images demonstrated the dispersion of Ni nanoparticles across the spherical form FSA, with 12.5Ni/ FSA exhibiting the most homogeneous distribution. The BET report indicated that when Ni loading was increased, the surface area of the catalysts increased to 645 m2/g via 12.5 % of Ni. However, in the case of 15Ni/FSA, Ni agglomeration was found. 12.5Ni/FSA gave the highest catalytic efficiency and stability (XCO2 = 82.16 %, XCH4 = 97.16 %, and H2/CO = 0.91). The stability test revealed no trace of deactivation after 60 h of time-on-stream. In concordance with the spent catalyst, XRD, Raman, and TGA investigations showed the graphitic carbon nonattendance for all spent Ni/FSA specimens, and the medium basicity noted by IR-pyrrole analyses, could be attributed to enhanced efficiency of the catalyst. According to the enhanced performance of 12.5Ni/FSA, there was a substantial synergistic impact between the Ni active metal sites and the FSA support, which boosted the reactivity based on both gaseous reactants, CH4 and CO2. The 12.5 wt% Ni was determined to be the optimum Ni value for inhibiting coke deposition on the FSA and hence improving catalytic performance.