Effects of niobium addition on active metal and support in Co–CeO2 catalyst for the high temperature water gas shift reaction

[Display omitted] •Nb-promoted Co–CeO2 catalysts were prepared; their performance was investigated.•Among the prepared catalysts, 1.5NbCo catalyst showed the highest performance.•The high performance resulted from a high OSC and Co dispersion.•1.5NbCo is a promising catalyst for hydrogen production via the WGS reaction. Nb promoter was introduced in the Co–CeO2 catalyst to improve its catalytic performance in the high temperature water gas shift (HT-WGS) reaction, which involves the production of hydrogen from waste-derived synthesis gas. Thereafter, the physicochemical properties of the promoter as well as those of the catalyst were investigated using various techniques. Thus, it was confirmed that the Nb promoter affects the key properties related to catalytic performance, including oxygen storage capacity (OSC) and dispersion. To maximize the positive effect of the Nb promoter, we further investigated the effect of the Nb loading amount on the performance of the catalyst. The results obtained showed that the 1.5NbCo catalyst exhibited the highest catalytic performance (XCO=89% at 450°C) under very severe conditions (gas hourly space velocity (GHSV)=637,320h−1). Additionally, this catalyst exhibited stable activity for 50h. This its high catalytic performance could be attributed to its high OSC and Co dispersion. Therefore, it is a promising catalyst for hydrogen production via the HT-WGS reaction.