Silica-Decorated NiAl-Layered Double Oxide for Enhanced CO/CO₂ Methanation Performance

CO/CO₂ hydrogenation has attracted much attention as a pathway to achieve carbon neutrality and production of synthetic natural gas (SNG). In this work, two-dimensional NiAl layered double oxide (2D NiAl-LDO) has been successfully decorated by SiO₂ nanoparticles derived from SiCl₄ and used as CO/CO₂ methanation catalysts. The as-obtained H-SiO₂-NiAl-LDO exhibited a large specific surface area of 201 m²/g as well as high ratio of metallic Ni⁰ species and surface adsorption oxygen that were beneficial for low-temperature methanation of CO/CO₂. The conversion of CO methanation was 99% at 400 °C, and that of CO₂ was 90% at 350 °C. At 250 °C, the CO methanation reached 85% whereas that of CO₂ reached 23% at 200 °C. We believe that this provides a simple method to improve the methanation performance of CO and CO₂ and a strategy for the modification of other similar catalysts.