This paper presents a comprehensive mechanistic investigation into the partial oxidation of methane to methanol on bare and ZSM-5-supported Pd 4 clusters utilizing N 2 O as an oxidant. The study employs density functional theory (DFT) with ONIOM2 (QM: MM) (B3PW91/LANL2DZ/6-31G(d,p):UFF) with dispersion correction calculations to explore potential energy surfaces (PESs) associated with the methane-to-methanol conversion process in a ZSM-5-supported Pd 4 cluster. Two spin multiplicities (SM = 1, 3) were considered for the overall reaction pathway. The investigation reveals that C−H activation of methane takes place subsequent to the formation of Pd 4 O from the N 2 O decomposition step, which ultimately leads to methanol formation. The study indicates that in terms of activation barrier, the N−O and C−H activation steps exhibit a lower energy barrier in the singlet state, while the recombination step of CH 3 and OH moieties is preferable in the triplet spin state. However, the reaction process does not involve any spin crossover, as the triplet spin state consistently maintains the lowest energy pathway throughout the reaction. From the overall analysis of the reaction mechanisms for methane to methanol, it is evident that zeolite support and spin multiplicity play a significant role in lowering the activation barriers.