Water gas shift activity of Au–Re catalyst over microstructured cordierite monolith wash-coated by ceria

Abstract

Water-gas shift (WGS) activity of 1.4 wt.% Au–0.2 wt.% Re/CeO2 catalyst was investigated over microchannel cordierite monolith as a low pressure drop and easy to miniaturize reactor structure for small size applications like fuel processors. The catalyst was prepared by wash-coating the colloidal ceria, which is believed to be one of the best support for WGS, over the wall of cordierite monolith followed by depositing Au and Re using homogeneous deposition–precipitation (HDP) method; then the WGS activity of the catalyst was tested in a microflow reactor. The SEM-EDS and ICP characterization tests were also performed. Initially, the monolithic Au/CeO2 had lower performance than the particulate catalyst but its activity improved significantly by adding Re as promoter and making some modifications in HDP method. Then 10% CO2 and 25% H2 was introduced to the feed (both separately and together) to simulate a realistic feed from a fuel processor, and both equilibrium and actual CO conversions were decreased as expected; however, the performance of monolithic Au–Re/CeO2 was still satisfactory indicating that this structure could have a potential for small scale medium temperature WGS applications.