The selective epoxidation of ethylene on Pd-doped C3N nanosheet (Pd@C3N) is investigated using dispersion-corrected DFT calculations. The electronic resonance between the Pd and its neighboring C atoms is shown to significantly activate the adsorbed O2 and C2H4 molecules on Pd@C3N. According to our results, the coadsorption of O2 and C2H4 molecules on Pd@C3N is more energetically feasible than a single O2 or C2H4 adsorption. The oxidation of ethylene on Pd@C3N is accomplished via two mechanisms, i.e., bimolecular (B-LH) and trimolecular Langmuir–Hinshelwood (T-LH). In both pathways, the ethylene oxide formation is favored over the acetaldehyde formation. The obtained activation barriers are comparable to those reported for Au-based catalysts. Moreover, the epoxidation of ethylene has a faster kinetics than the formation of acetaldehyde. Also, the effects of temperature and entropy are studied on the rate-determining steps of the B-LH and T-LH mechanisms.
