Synthesis of Porous Ni/SiC(O)-Based Nanocomposites: Effect of Nickel Acetylacetonate and Poly(Ethylene Glycol) Methacrylate Modification on Specific Surface Area and Porosity

Abstract

Nanoporous Ni/SiC(O)-based nanocomposites are successfully synthesized by the pyrolytic conversion of nickel-modified polycarbosilane precursors, which are obtained by the chemical modification of polycarbosilane with nickel acetylacetonate (Ni-SMP). High-temperature treatment of the produced precursor in argon atmosphere leads to the homogeneously distributed in situ generated crystalline Ni nanoparticles in the amorphous SiC(O) matrix. The obtained Ni/SiC(O)-based nanocomposites show high specific surface area (SSA; 100–200 m2 g−1) with in situ generated microporosity. Furthermore, the chemical modification of Ni-SMP precursor with macromolecule poly(ethylene glycol) methacrylate (PEGM) increases the SSA (Ni-SMP-PEGM; 300–350 m2 g−1) and generated micro-mesoporosity. In terms of catalytic properties, preliminary results of the catalytic activity of the Ni/SiC(O)-based nanocomposites show that they are active for the methanation of CO2. The CO2 conversion increases with increasing reaction temperature and decreases with increasing nanocomposite pyrolysis temperature. The maximum CO2 conversion efficiency is found for the Ni-SMP-PEGM-600 (46%) at reaction temperature of ≈500 °C.