The oxidation functionality of Mn(IV) sites has been assessed by density functional theory (DFT) analysis of adsorption and activation energies of CO, H₂ and O₂ on a model Mn₄O₈ cluster. DFT calculations indicate that Mn(IV) atoms prompt an easy CO conversion to CO₂ via a reaction path involving both catalyst and gas-phase oxygen species, while much greater energy barriers hinder H₂ oxidation. Accordingly, a MnCeO_x catalyst (Mn_at/Ce_at, 5) with large exposure of Mn(IV) sites shows a remarkable CO oxidation performance at T ≥ 293 K and no H₂ oxidation activity below 393 K. Empiric kinetics disclose that the catalyst-oxygen abstraction step determines both CO and H₂ oxidation rate, although different activation energies favor the preferential oxidation (PROX) pattern of the studied catalyst (353–423 K). Conversion-selectivity of 100%, high stability during 72 h reaction time and moderate inhibiting effects of water and CO₂ feeding reveal the potential of MnO₂ materials as efficient, low-cost and robust PROX catalysts.

Mn(IV) 位点的氧化功能已通过对模型Mn ₄ O ₈簇上CO、H ₂和O ₂的吸附和活化能的密度泛函理论(DFT) 分析进行评估。DFT 计算表明，Mn(IV) 原子通过涉及催化剂和气相氧物种的反应路径促使 CO 容易转化为 CO ₂，而更大的能量势垒阻碍了 H ₂氧化。因此，具有大量 Mn(IV) 位点暴露的MnCeO _x催化剂（Mn _at /Ce _at , 5）在 T ≥ 293 K 且无 H _{2 时}表现出显着的 CO 氧化性能低于 393 K 的氧化活性。经验动力学表明，催化剂-氧气提取步骤决定了 CO 和 H _{2 的}氧化速率，尽管不同的活化能有利于所研究催化剂的优先氧化 (PROX) 模式 (353-423 K)。100% 的转化选择性、72 小时反应时间内的高稳定性以及水和 CO ₂进料的适度抑制作用揭示了 MnO ₂材料作为高效、低成本和坚固的 PROX 催化剂的潜力。