Catalytic decomposition of N2O on iron-embedded C2N monolayer: A DFT study

Abstract

In order to control and decompose nitrous oxide (N2O), an economical and efficient catalyst is needed. Here, the N2O reduction mechanism using recently synthesized Iron-embedded C2N monolayer (Fe@C2N) as catalyst ware investigated by density functional theory (DFT). The results show that N2O is chemisorbed on Fe@C2N due to the strong interaction with Fe atoms and shows better reactivity than pristine C2N. The N2O reduction process proceeds via a two-step mechanism: (i) N2O → N2 + O*, (ii) CO + O* →CO2, or N2O + O* → N2 + O2. In the first step, the energy barrier for the decomposition of N2O is 8.4 kcal/mol. After N2O is decomposed, the reaction energy barrier of the second step is only 3.2 kcal/mol, which is much lower than precious metal-based catalysts. In particular, in the second step of the reaction, N2O can achieve self-reduction, and its energy barrier is 18.8 kcal/mol. However, the activation energy is not high enough to inhibit the reaction and it is much lower than other typical catalysts, which means that Fe@C2N can realize the N2O reduction process without using CO as a reductant. Therefore, Fe@C2N exhibits excellent catalytic performance for N2O reduction and can be realized under normal temperature conditions.