Water gas shift reaction on the Mn-modified ordered mesoporous Co₃O₄

The novel Mn-modified ordered mesoporous Co₃O₄ catalysts were investigated for water gas shift reaction (WGSR), which was synthesized through a nano-casting method using a hard template of KIT-6. An incipient wetness impregnation of Mn precursor with different concentrations was applied for preparing Mn-modified mesoporous Co₃O₄. On 15 wt%Mn impregnated mesoporous Co₃O₄ (denoted as Mn(15)/meso-Co₃O₄), WGSR activity was found to be higher among the tested catalysts due to a higher structural stability of the Co₃O₄ mesopores with a larger surface area. The Mn(15)/meso-Co₃O₄ also showed stable ordered mesopore structures with an exposed larger number of active metallic cobalt sites on the surfaces even after WGSR. The structural stability was mainly attributed to the strong and stable interactions between cobalt oxides and manganese oxides. With an optimum amount of Mn promoter, Mn plays an important role as a structural stabilizer of the mesoporous Co₃O₄ as well as an electron modifier by enhancing redox cycle properties of cobalt species and fast mass transport in mesopores.