Efficient CO oxidation over palladium supported on various MOFs: Synthesis, amorphization, and space velocity of hydrogen stream

Amine-functionalized MIL-101(Cr) has been synthesized by hydrothermal (MNH2) and post-synthetic modification (MNH2-p) approaches. Pd/MNH2 and Pd/MNH2-p have been tested in CO oxidation reaction as a gas phase reaction to clarify the difference between two synthesis approaches. Their performance has also been compared with that of Pd supported on MIL as a common MOF and CuBTC as a commercial one. The results show the significant difference between Pd/MNH2-p and Pd/MNH2, where CO conversion of 100% was not observed for Pd/MNH2-p, whereas Pd/MNH2 outperformed the others and exhibited the high reaction rate thanks to the active sites created by amorphization during the reduction process because of impressive effect of hydrogen on its structure. The effect of Space Velocity of Reduction Stream (SVr) has also been studied and the results show that the activity of Pd/CuBTC dramatically enhances at higher SVr and its activity further improves as a result of the formation of 8.9 nm CuO nanoparticles during the CO oxidation process.