Synthesis, Characterization, and CO₂ Methanation Over Hierarchical ZSM‐5‐NiCoAl Layered Double Hydroxide Nanocomposites: Improvement of C−C Coupling to Ethane

Abstract

To date, preparing materials with highly dispersed metal nanoparticles without metal agglomeration on a solid support is challenging. This work presents an alternative approach for synthesizing NiCo species on hierarchical ZSM‐5 materials derived from a core‐shell ZSM‐5@NiCoAl‐LDHs composite. The designed material was prepared by the growth of a NiCo‐LDHs precursor on the surface of hierarchical ZSM‐5 nanosheets. The effect of the weight ratio of NiCo‐LDHs precursor to ZSM‐5 on the composite properties has been studied. The results show that 45 wt.% LDHs is the most suitable condition for preparing NiCoAl‐LDHs/ZSM‐5 composite with a core‐shell structure, which promotes a strong interaction between bimetallic NiCo and hierarchical ZSM‐5. The ZSM‐5@NiCoAl‐LDHs‐45 showed a BET surface of 386 m2.g‐1, in which the surface area has been re‐allocated between microspores and mesopores due to the presence of NiCoAl‐LDHs composite. The catalyst was also tested for CO2methanation at 380 °C under atmospheric hydrogen pressure. The results show that the catalyst could provide CO2conversion of up to 40% at WSHV of 2.91 h‐1. Interestingly, it could not only promote methane but also provide a high selectivity of ethane, approximately 20.4%. Moreover, the excellent catalytic stability of ethane production was illustrated over 24 hours of time‐on‐stream.