Efficient Utilization of Silanol Group in Biomass to Promote the Synthesis of Ni-Phyllosilicate for Co2 Methanation

It was a challenge to prepare nickel phyllosilicate with high catalytic activity using biomass-based silica as substrate due to the low Ni content. In order to efficiently utilize the abundant silanol group in silica-contained biomass, the acid-treated rice husk without calcination (P-R) was directly used as the raw material to prepare the Ni-phyllosilicate. The as-synthesized sample (N/P-R) exhibited high nickel content of 46.7 wt%, which was much higher than that of the sample (N/R-S) prepared using the conventional biomass-based silica of 4.8 wt%. As a result, N/P-R displayed much higher catalytic activity for CO 2 methanation than N/R-S. The P-R had a large content of silanol groups which was in favour of forming the important intermediate Si(OH) 4 , and thereby promoted the formation of nickel phyllosilicate. In addition, the N/P-R catalyst demonstrated superior stability and excellent anti-sintering ability in the long lifetime test. In short, the proposed method in this work could not only efficiently synthesize nickel phyllosilicate with high Ni content, but also reduce energy consumption and operation steps compared to the one prepared using biomass-based silica