Promotion of methanation suppression by alkali and alkaline earth metals in Ni-CeO2 catalysts for water-gas shift reaction using waste-derived synthesis gas

In this study, alkali and alkaline earth metal-promoted Ni-CeO2 catalysts were developed for the high temperature water-gas shift reaction of waste-derived synthesis gas in which hydrogen is produced. The elements K, Ca, Mg, and Ba were selected to repress methanation, which is a major side reaction of Ni-based catalysts. The prepared catalysts were characterized using different techniques including the Brunauer-Emmett-Teller method, X-ray diffraction, H-2-temperature programmed reduction, CO2-temperature programmed desorption, H-2-chemisorption, and X-ray photoelectron spectroscopy to determine the correlations between the catalyst activity and their properties. The results show that the alkali and alkaline earth metal promoted Ni-CeO2 catalyst effectively suppressed methanation. Among the promoted catalysts, the Ca/NiCeO2 catalyst exhibited the highest activity and stability for 18 h at a very high gas hourly space velocity of 1,050,957 h(-1), which is mainly due to the high oxygen storage capacity.

Automated summary

In this study, alkali and alkaline earth metal-promoted Ni-CeO2 catalysts were developed for the water-gas shift reaction to increase hydrogen production by suppressing methanation. Various characterization techniques were employed to determine the relationship between catalyst activity and properties. The results showed that the promoted Ni-CeO2 catalysts effectively suppressed methanation, with the Ca/NiCeO2 catalyst exhibiting the highest activity and stability due to its high oxygen storage capacity.