Synthesis and characterization of perovskite-supported CoNi catalyst for CO oxidation via exsolution

Abstract

The introduction of perovskite oxide as catalysts alternative has increased the worldwide interest due to its advantages such as its versatility to accommodate different transition metals. This study set out to evaluate the catalytic activity of CO oxidative perovskite catalysts (LCCNTO), fabricated via solid-state method and reduced under various reducing condition for the exsolution of the active metals, Cobalt-Nickel (CoNi) from the perovskite lattice. The effect of reducing parameter modification towards the catalytic activity of the fabricated LCCNTO was discussed in terms of CO conversion and CO2 production rate. Through the light-off test, the sample that reduced with the longest deration (S2T10H6-R5H5) showed the highest CO conversion of 45.45% and CO2 production rate of 0.1409 × 10−4 mol s− 1g−1 at the reaction temperature of 500 °C. Not only that, it was discovered that by controlling the reducing duration, the initiate temperature for the reaction to occur was lowered from 360 °C (S2T10H6-R5H3) enabling the reaction to occur at lower temperature at 280 °C in S2T10H6-R5H5. Under the same reducing temperature, the CO2 production of sample reduced for 200 minutes (S2T10H6-R5H3) started at 360 °C but as the reducing duration increased to 300 minutes (S2T10H6-R5H5), the CO oxidation initiated at a much lower temperature of 280 °C. Although LCCNTO catalyst still suffer from similar deterioration as the other reported base metal catalyst, but tuning the reducing duration given to a sample, it greatly affects the initiation temperature for the reaction to occur.