Two-dimensional porous SiO₂ nanomesh supported high dispersed Ni nanoparticles for CO methanation

Two-dimensional (2D) porous SiO₂ nanomesh obtained from mixed acid etching of vermiculite (VMT) was successfully used as a catalyst support for CO methanation. Compared with three-dimensional (3D) MCM-41, 2D VMT-SiO₂ provided a superior position for implantation of NiO species. Although NiO/VMT-SiO₂ has a total loading of 10 wt.% NiO as well as the NiO/MCM-41, the NiO particles on VMT-SiO₂ were observed to show a better dispersion as the of 3D MCM-41 channels were easily blocked by large NiO particles. Moreover, on the basis of the H₂ temperature-programming reduction results, NiO particles on VMT-SiO₂ were more easily reduced than those on MCM-41. These characteristics indicated that NiO/VMT-SiO₂ was significantly superior to NiO/MCM-41. The as-obtained NiO/VMT-SiO₂ exhibited a CO conversion of 85.9%, CH₄ selectivity of 78% at 450 °C, 0.1151 s⁻¹ turn over frequency at 320 °C and a gas hourly space velocity of 20745 ml/g/h. All of which were much better than those measured for NiO/MCM-41. We believed that 2D VMT-SiO₂ as a new catalyst support open a prospect application of catalyst.