High-performance catalysts are extremely required for controlling NO emission via selective catalytic reduction (SCR), and to acquire a common structural feature of catalytic sites is one key prerequisite for developing such catalysts. We design a single-atom catalyst system and achieve a generic characteristic of highly active SCR catalytic sites. A single-atom Mo₁/Fe₂O₃ catalyst is developed by anchoring single acidic Mo ions on (001) surfaces of reducible α-Fe₂O₃, and the individual Mo ion and one neighboring Fe ion are thus constructed as one dinuclear site. As the number of the dinuclear sites increases, SCR rates increase linearly but the apparent activation energy remains almost unchanged, evidencing the identity of the dinuclear active sites. We further design W₁/Fe₂O₃ and Fe₁/WO₃ and find that tuning acid or/and redox properties of dinuclear sites can alter SCR rates. Therefore, this work provides a design strategy for developing improved SCR catalysts via optimizing acid-redox properties of dinuclear sites.

高性能催化剂是通过选择性催化还原（SCR）控制NO排放所必需的，而获得催化部位的共同结构特征是开发此类催化剂的关键先决条件。我们设计了一个单原子催化剂系统，并实现了高活性SCR催化位的一般特征。单原子沫₁ / Fe的₂ ö ₃可还原的催化剂是通过在（001）锚定单一酸性钼离子表面开发的α-Fe ₂ ö ₃因此，将单个的Mo离子和一个相邻的Fe离子构造为一个双核位点。随着双核位点数量的增加，SCR速率线性增加，但表观活化能几乎保持不变，证明了双核活性位点的身份。我们进一步设计了W ₁ / Fe ₂ O ₃和Fe ₁ / WO ₃，发现调节双核位点的酸或氧化还原性质可以改变SCR率。因此，这项工作为通过优化双核位点的酸-氧化还原性能开发改进的SCR催化剂提供了一种设计策略。