Enhanced catalytic performance of CO methanation over VOx assisted Ni/MCF catalyst†
In this work, mesostructured cellular foam silica (MCF) was used as the support to prepare a series of Ni–VOx/MCF catalysts for CO methanation using an incipient impregnation method. The samples were characterized by nitrogen adsorption, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, H2 temperature-programmed reduction, H2 temperature-programmed desorption, and X-ray photoelectron spectroscopy. Among all the catalysts, Ni–VOx/MCF with NiO of 10 wt% and V2O5 of 3 wt% (Ni–3V/MCF) showed the best catalytic performance, which reached its maximum CO conversion and CH4 yield of 98.9% and 93.2%, respectively, at 350 °C. Ni–3V/MCF exhibited high stability in a 100 h-lifetime test, which was carried out at a constant temperature of 450 °C for 100 h at 0.1 MPa and a high weight hourly space velocity (WHSV) of 60 000 mL g−1 h−1. The addition of VOx promoter in Ni/MCF could not only improve the dispersion of Ni nanoparticles, but also increase the electron density of Ni, resulting in the enhanced dissociation of C–O bonds and improved catalytic activity of the catalysts.