Strong NiOx and ZrO2 interactions to eliminate the inhibiting effect of trace oxygen for propane dehydrogenation by accelerating lattice oxygen releasing

Recently, the ZrO2-based catalysts for PDH exhibited high activity owing to the formation of oxygen vacancy and coordinatively unsaturated Zr (Zrcu) sites. However, industrial C3H8 raw gases typically contain trace amounts of oxygen at 10–1000 ppm, which can significantly decrease the PDH activity of nano-sized ZrO2 catalyst, because that oxygen vacancy can be filled by the O2 molecules rapidly, while the rate of lattice oxygen consumption is relatively slow. Here, highly dispersed NiOx species loading on ZrO2 significantly increased C3H6 formation rate (up to 6.6 times) and decreased the activation energy. The strong interaction between NiOx species and ZrO2 enhances the ability of ZrO2 to release its lattice oxygen, and increases the concentration of oxygen vacancy and unsaturated Zr-O acid-base pairs for PDH. This strategy can expand to other metal oxides interacted with ZrO2 to eliminate the inhibiting effect of trace oxygen, such as GaOx, CoOx, CrOx, LaOx, and InOx.