Insight into NOx removal mechanism by H2O2 activation via MIL-100(Fe) in an alkaline environment

In this study, we used a metal-organic framework (MOF) material named MIL-100(Fe) as a catalyst to activate the H2O2/NaOH system for the efficient removal of NOx. OH- attack the Fe-O bond to break it and Fe(III) is released into the solution & sdot;H2O2 decomposes to HO2- in an alkaline environment and Fe(III) in the dissolved state reacts with it, producing Fe(II) and center dot O2- . The MOF material had a strong electron transfer capability, facilitating the efficient conversion of Fe(III) to Fe(II) by transferring the electrons released during the NO conversion process. This electron transfer process played a crucial role in slowing down the rate of pH increase in the solution and enhancing the utilisation of H2O2. The main reactive oxygen species in this reaction are center dot O2- and center dot OH. By further analyzing the products of the quenching experiments, we propose an interaction mechanism between NO and center dot O2- as well as center dot OH.