Effect of the Preparation Method of LaSrCoFeOx Perovskites on the Activity of N2O Decomposition

N2O remains a major greenhouse gas and contributor to global warming, therefore developing a catalyst that can decompose N2O at low temperatures is of global importance. We have investigated the use of LaSrCoFeOx perovskites for N2O decomposition and the effect of surface area, A and B site elements, Co-O bond strength, redox capabilities and oxygen mobility have been studied. It was found that by using a citric acid preparation method, perovskites with strong redox capabilities and weak Co-O bonds can be formed at relatively low calcination temperatures (550 degrees C) resulting in highly active catalysts. The enhanced activity is related to the presence of highly mobile oxygen species. Oxygen recombination on the catalyst surface is understood to be a prominent rate limiting step for N2O decomposition. Here the reduced strength of Co-O bonds and mobile lattice oxygen species suggest that the surface oxygen species have enhanced mobility, aiding recombination, and subsequent regeneration of the active sites. La0.75Sr0.25Co0.81Fe0.19Ox prepared by citric acid method converted 50% of the N2O in the feed (T-50) at 448 degrees C.

Automated summary

The study demonstrates that catalysts with strong redox capabilities and weak Co-O bonds can be formed at lower temperatures using a citric acid preparation method, leading to enhanced activity for N2O decomposition. The mobility of surface oxygen species is crucial for the improved activity, and the recombination of oxygen on the catalyst surface plays a key role in the rate-limiting step for N2O decomposition.