WO₃ and MoO₃ are widely used as the additives for the V₂O₅-based selective catalytic reduction (SCR) catalysts, which have different anti-arsenic poisoning performances. To clarify their different influence mechanism on the interaction between arsenic oxide (As₂O₃) and the V₂O₅-based catalyst, WO₃ and MoO₃ doped V₂O₅/TiO₂ catalyst models were built, density functional theory (DFT) method was employed to explore the interaction mechanism for As₂O₃ with V₂O₅, WO₃ and MoO₃ from a theoretical level. As₂O₃ adsorption configurations, adsorption energies and electronic structures were obtained, along with the detailed inter-reaction pathways and relevant energy barriers. The results indicate that strong interaction and electron transfer occur after As₂O₃ adsorption, the MoO₃ doped catalyst has higher reactivity and stronger charge transfer with As₂O₃ than the WO₃ doped catalyst. Moreover, on V₂O₅-WO₃/TiO₂ catalyst, the reactivity of WO₃ with As₂O₃ is lower than that of V₂O₅, hence As₂O₃ is inclined to react with V₂O₅, resulting in the catalyst deactivation. Whereas for V₂O₅-MoO₃/TiO₂ catalyst, As₂O₃ tends to react with the more active MoO₃, thus protecting the V₂O₅ from arsenic poisoning. In summary, MoO₃ doping provides better anti-arsenic poisoning effect than WO₃, which agrees well with previous experimental results.

WO ₃和MoO ₃被广泛用作基于V ₂ O ₅的选择性催化还原（SCR）催化剂的添加剂，这些催化剂具有不同的抗砷中毒性能。为了阐明它们对氧化砷（As ₂ O ₃）和V ₂ O ₅基催化剂之间相互作用的不同影响机理，建立了WO ₃和MoO ₃掺杂的V ₂ O ₅ / TiO ₂催化剂模型，密度泛函理论（用DFT）方法研究了As ₂ O ₃与V的相互作用机理从理论上讲是₂ O ₅，WO ₃和MoO ₃。作为₂ O _3的吸附构型，获得了吸附能和电子结构，以及详细的相互作用路径和相关的能垒。结果表明，As ₂ O ₃吸附后发生了较强的相互作用和电子转移，MoO ₃掺杂的催化剂比WO ₃掺杂的催化剂具有更高的反应性和更强的As ₂ O ₃电荷转移能力。此外，在V ₂ O ₅ -WO ₃ / TiO _2上催化剂，WO ₃与As ₂ O ₃的反应性低于V ₂ O ₅，因此As ₂ O ₃倾向于与V ₂ O ₅反应，导致催化剂失活。而对于V ₂ O ₅ -MoO ₃ / TiO ₂催化剂，As ₂ O ₃倾向于与活性更高的MoO ₃反应，从而保护V ₂ O ₅免受砷中毒。总而言之，MoO ₃掺杂提供比WO ₃更好的抗砷中毒效果，这与以前的实验结果非常吻合。