Synthesis of Ni-phyllosilicate Assisted by Fluoroboric Acid for CO2 Methanation

How to efficiently prepare nickel phyllosilicate using the calcined biomass-based silica as the sacrificial template under the mild condition is a challenge. In this work, NH4HF2, H2SiF6 and HBF4 were used as the assistor to facilitate the synthesis of Ni-phyllosilicate, which could be successfully synthesized under the mild condition of 120 & DEG;C for 12 h. Compared with NH4HF2 and H2SiF6, HBF4 was the best fluorine-containing assistor. The HBF4-assisted Ni phyllosilicate catalyst (Ni-Ps/B) exhibited the high CO2 conversion of 80.0% and CH4 selectivity of 98.3% at 450 & DEG;C due to its small particle size of 3.8 nm, high Ni content of 21.65 wt% as well as enhanced H2 and CO2 desorption capacity. The charac-terization results showed that HBF4 converted to B2O3 after the hydrothermal reaction and thermal treatments, which could not only provide the physical barrier for Ni species during reduction process, but also be a promoter for Ni-Ps/B for CO2 methanation. In all, HBF4 was a competitive fluorine-containing assistor for the highly efficient synthesis of Ni-phyllosilicate catalysts. & COPY; 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.