Monometallic and bimetallic SiC(O) ceramic with Ni, Co and/or Fe nanoparticles for catalytic applications

Abstract

Abstract Monometallic (Ni, Co or Fe-SiC(O)) and bimetallic (Ni, Co or FeM-SiC(O) with M = Ni or Co) ceramic nanocomposites have been successfully prepared using polymeric precursors obtained by chemical modification of polycarbosilane with metal acetylacetonate. The nanocomposites consist of homogeneously distributed metal nanoparticles within an amorphous SiC(O). The specific surface area (SSA) of Ni, Co or Fe-SiC(O)600 nanocomposites were found to be 155, 50 or 14 m2/g. However, the addition of Fe to the Ni-or Co-containing precursors tends to increase the SSA to 290 or 170 m2/g. Maximum CO2 conversion for monometallic samples was found to be 40% at 500 °C for Ni-SiC(O)600 and maximum CH4 selectivity was 61% at 300 °C for Co-SiC(O)600. The additional presence of Co and Ni in the respective nanocomposites helps to increase the CO2 conversion and selectivity at 500 °C whereas Fe modification shows high methane selectivity at lower temperature < 350 °C. Graphical Abstract Highlights Novel nanocomposites consist of bimetallic and SiC(O) ceramic with high specific surface area (SSA) for catalytic applications synthesized via polymer-derived route. Homogeneously distributed metal nanoparticles (5–7 nm) within amorphous SiC(O) ceramics. Among monometallic composites, Ni-SiC(O) and Co-SiC(O) show better catalytic results in methanation reaction than Fe-SiC(O). Introduction of second metal (Ni, Co or Fe) into Ni and Co-SiC(O) ceramic nanocomposites enhances the SSA and catalytic activity in methanation reaction. In bimetallic nanocomposites Ni and Co increase the catalytic activity and selectivity whereas Fe helps to improve the selectivity at lower temperature.