H₂O is often critical in determining the activity and stability of metal oxide catalysts for HCHO oxidation; however, synthesis of metal oxide catalysts with super resistance to H₂O remains a challenging. Herein, we synthesized Akhtenskite-type MnO₂ catalyst with Mn–O–Mn stretching along MnO₆ octahedra layers, which promotes the utilization of the associatively adsorbed H₂O. The activity and stability of formaldehyde oxidation at room temperature enhanced in humid air. Diffuse-reflectance infrared Fourier transform (DRIRFT) spectroscopy was used to characterize the H₂O adsorption and intermediate species. The associatively adsorbed H₂O promotes the oxidation of formaldehyde to CO₂ via the formic acid intermediate. The service life of MnO₂ is prolonged due to formic acid generation. MnO₂ gradually deactivates when formic acid accumulates and forms formate and hydrogen carbonate species. This study provides significant insights into the development of a high-efficiency MnO₂ catalyst for formaldehyde oxidation in humid air, and the developed MnO₂ catalyst is a promising candidate for application in practical formaldehyde elimination.

H ₂ O通常对于确定用于HCHO氧化的金属氧化物催化剂的活性和稳定性至关重要。然而，合成金属氧化物催化剂对H ₂ O具有超强的抵抗力仍然是一个挑战。在这里，我们合成了沿着MnO ₆八面体层伸展Mn–O–Mn的Akhtenskite型MnO ₂催化剂，这促进了缔合吸附H ₂ O的利用。在潮湿空气中，室温下甲醛氧化的活性和稳定性得到增强。漫反射红外傅里叶变换（DRIRFT）光谱用于表征H ₂ O吸附和中间物种。缔合吸附的H ₂O通过甲酸中间体促进甲醛氧化为CO ₂。由于甲酸的产生，MnO _2的使用寿命得以延长。当甲酸积累并形成甲酸根和碳酸氢根时，MnO ₂逐渐失活。这项研究为开发用于湿空气中甲醛氧化的高效MnO ₂催化剂提供了重要的见识，而开发出的MnO ₂催化剂在实际的甲醛消除中具有广阔的应用前景。