Sol-Gel Synthesized SiO2 Supported Ni-Al LDH Nanocomposite Based Mixed-Metal Oxide Catalyst for the Conversion of High GWP Gas From N2O to N2 and O2

Abstract

Layered Double Hydroxides (LDH) are the 2D nanomaterials having the general formula [M_1-x²⁺M_x³⁺(OH)₂]^x+[A_x/n]ⁿ⁻.mH₂O. They become one of the most promising catalysts for various applications because of their many unique properties, which include high surface area, uniform atomic level distribution, and acid-base bifunctionality. In this work metal acetylacetonate was used as a precursor to synthesize Ni-Al and its SiO₂-supported product by the nonaqueous sol-gel method. PXRD, FT-IR, TGA, BET surface area and pore volume analysis, Zeta potential, particle size analysis, SEM, TEM, and EDS analysis were used to characterize them. The mixed-metal oxides were obtained by calcinations of the synthesized LDHs at 450 °C. The resulting mixed metal oxide was subsequently employed as a catalyst for the N₂O decomposition process. When the SiO₂: LDH ratio varied, these catalysts showed improved N₂O decomposition at 450 °C with the changes of SiO₂: LDH ratio. In the presence of SiO₂: LDH ratios of (2:1) and (1:2), around 99.5% of N₂O conversion was noted.