Effect of concentration of nickel precursor on the synthesis of Ni phyllosilicate for CO2 methanation: The promotion of supersaturation

Abstract

In order to facilitate the synthesis of nickel phyllosilicate through hydrothermal method, the effect of different concentration of Ni(NO3)2 aqueous solutions on nickel phyllosilicate synthesis was investigated in this work. It was found that Ni-phyllosilicate could hardly been formed at the low concentration of the Ni(NO3)2 aqueous solution (0.05 mol･L−1), and a small amount of Ni-phyllosilicate was formed when the concentration increased to 0.10 mol･L−1. The double solvent system of H2O and cyclohexane could further enhance the formation of Ni-phyllosilicate due to the promotion of supersaturation. Furthermore, the N/M-D-A-120 catalyst prepared in the presence of double solvent and the accelerators of NH4F and urea exhibited high Ni content and small Ni crystal size, leading to the high catalytic activity and long-term stability for CO2 methanation. In short, the concentration of Ni(NO3)2 aqueous solution was an important factor for the efficient formation of Ni-phyllosilicate, and the construction of double solvent of H2O and cyclohexane could further increase the supersaturation and enhance the Ni-phyllosilicate synthesis.