Optimization of Co-precipitation Condition for Preparing Molybdenum-Based Sulfur-Resistant Methanation Catalysts

Abstract

In this study, the effects of ZrO2 carrier precursors, MoO3 loading, and washing treatment on the catalytic performance of MoO3/ZrO2 toward sulfur-resistant methanation were investigated. All the catalysts were prepared by co-precipitation method and further characterized by N2 adsorption–desorption, H2-temperature-programmed reduction, X-ray diffraction, Raman spectroscopy and transmission electron microscopy. The prepared MoO3/ZrO2 catalysts were tested in a continuous-flow pressurized fixed bed reactor for CO methanation. The results revealed that the carrier precursors, MoO3 loading, and washing treatment affected not only the crystalline phase of Mo species but also the grain size of ZrO2 carrier and consequently influenced the MoO3/ZrO2 activity toward sulfur-resistant methanation. The 25 wt% MoO3/ZrO2 catalyst prepared using Zr(NO3)4·5H2O as the precursor and treated by water washing displayed the best activity for sulfur-resistant methanation due to its greater number of octahedral Mo species and smaller ZrO2 grain size.