Vanadia-based catalysts are widely used in the selective catalytic reduction of NO_x with NH₃ (NH₃-SCR) for NO_x abatement. However, the effect of water on specific vanadyl species is still unclear. Herein, the temperature-dependent sensitivity of vanadyl species to water has been originally elucidated via operando Raman spectroscopy. Interestingly, the stronger competitive adsorption of NH₃ on polymeric vanadyl species in the presence of H₂O dominants the NH₃-SCR reaction above 250 °C despite the polymeric vanadyl show stronger adsorption to H₂O than the monomeric ones. By contrast, the association of water molecules via hydrogen bonding dominants the activity degeneration to both monomeric and polymeric vanadyl species at temperatures below 250 °C. Furthermore, the stronger adsorption of water on polymeric vanadyl will give rise to even worse degeneration. This work elucidates the interaction of vanadyl species with water, which is essential for the development of high-performance catalysts for water-tolerant NO_x abatement.

钒基催化剂广泛用于用 NH ₃ (NH ₃ -SCR)选择性催化还原 NO _{x以减少 NO x}。然而，水对特定氧钒种类的影响仍不清楚。在此，钒基物种对水的温度依赖性敏感性最初是通过操作拉曼光谱阐明的。_{有趣的是，在 H 2} O存在下，NH ₃对聚合氧钒物种的更强竞争吸附在250 °C 以上时占主导地位，尽管聚合氧钒对 H _{2表现出更强的吸附性}O 比单体的。相比之下，在低于 250 °C 的温度下，水分子通过氢键结合主导了单体和聚合氧钒的活性退化。此外，聚合氧钒对水的更强吸附会导致更严重的退化。_{这项工作阐明了钒基物质与水的相互作用，这对于开发用于减少耐水 NO x}的高性能催化剂至关重要。