The CO removal performances of Cr-free Fe/Ni catalysts for high temperature WGSR under LNG reformate condition without additional steam

The goal of this study was to investigate Cr-free, Fe/Ni, metal oxide catalysts for the high temperature shift (HTS) reaction of a fuel processor using liquefied natural gas (LNG). As hexavalent chromium (Cr6+) in commercial HTS catalyst is a hazardous material, we selected Ni as a substitute for chromium in the Fe-based HTS catalyst and investigated the HTS activities of these Cr-free, metal oxide catalysts under the LNG reformate condition. Cr-free, Fe/Ni-based catalysts containing Ni instead of Cr were prepared by coprecipitation and their performance was evaluated under a gas mixture condition (56.7% H2, 10% CO, 26.7% H2O, and 6.7% CO2) that simulated the gas composition from a steam methane reformer (SMR, at H2O/CH4 ratio = 3 with 100% CH4 conversion). Under this condition, the Fe/Ni catalysts showed higher CO removal activities than Fe-only and Cr-containing catalysts, but the methanation was promoted when the Ni content in the catalyst exceeded 50 wt%. Brunner-Emmett-Teller (BET), X-ray diffraction (XRD), inductively coupled plasma (ICP) and X-ray photoelectron spectroscopy (XPS) analyses were performed to explain the HTS activity of the Fe/Ni catalysts based on the catalyst structure.

► Fe/Ni as catalyst precursors. ► Catalysts for high temperature water gas shift reaction. ► Catalysts were evaluated under LNG reformate condition without additional steam. ► Fe/Ni showed high CO removal activity.