Improving the Catalytic Performance of Cobalt for CO Preferential Oxidation by Stabilizing the Active Phase through Vanadium Promotion

Preferential oxidation of CO (COPrOx) is a catalytic reaction targeting the removal trace amounts from hydrogen-rich gas mixtures. Non-noble metal catalysts, such as Cu and Co, can be equally active to Pt for reaction; however, their commercialization limited by poor stability. We have recently shown that CoO most state cobalt COPrOx, but under certain conditions, it readily oxidized Co3O4 deactivates. Here, we report simple method stabilize Co2+ vanadium addition. The V-promoted catalyst exhibits considerably higher activity stability than pure cobalt. nature sites during COPrOx was established operando NAP-XPS NEXAFS, while on surface verified in situ NEXAFS at 1 bar pressure. phase consists an ultra-thin cobalt-vanadate layer, containing tetrahedral V5+ octahedral cations, with electronic geometric structure deviating standard mixed bulk oxides. In addition, V addition helps maintain population species involved reaction, inhibiting carbonate formation are responsible deactivation. promoting effect discussed terms enhancement redox induced structural modifications. These results demonstrate promising validate application spectroscopy provide concept designing better performing catalysts.