The effect of different crystalline phases of Al₂O₃ (γ-Al₂O₃, γ, θ-Al₂O₃) on HCHO oxidation over Ag catalysts is investigated, and the silver state and particle size strongly depend on the Al₂O₃ crystalline phase. The various coordinatively unsaturated Al³⁺ (Al_Ⅲ, Al_Ⅴ) involves in the formation of Ag-O-Al entities. Ag species is mainly anchored on Al_Ⅴ sites for γ-Al₂O₃, whereas mainly on Al_Ⅲ sites for γ, θ-Al₂O₃. The weaker interaction of Ag, O and Al_Ⅴ on γ-Al₂O₃ compared with that of Ag, O and Al_Ⅲ on γ, θ-Al₂O₃ and the larger surface area of γ-Al₂O₃ result in the formation of more Ag⁰ with high dispersion. The higher fraction of coordinated Al_Ⅵ on γ-Al₂O₃ provides more adjacent hydroxyl groups for HCHO adsorption and formation of intermediates. And the synergistic effect of OH group and the high activation ability for oxygen on smaller Ag⁰ particles give the high HCHO oxidation activity on Ag/γ-Al₂O₃ (T₁₀₀ = 85 °C).

的Al的不同结晶相的效果₂ ö ₃（γ-Al系₂ ö ₃，γ，θ-Al系₂ ö ₃）上HCHO氧化的Ag的催化剂进行了研究，并且银状态和颗粒尺寸强烈依赖于在Al ₂ O ₃结晶相。各种配位不饱和的Al ³⁺（_AlⅢ，_AlⅤ）参与了Ag-O-Al实体的形成。银物种主要锚定对Al _Ⅴ位点的γ-Al ₂ ö ₃，而主要是对Al _Ⅲ位点γ，θ-Al系₂ ö ₃。的银，O和铝较弱相互作用_Ⅴ上的γ-Al ₂ ö ₃与的银，O和铝相比_Ⅲ上γ，θ-Al系₂ ö ₃和γ-Al系的更大的表面区域₂ ö ₃中结果形成更多具有高分散性的Ag ⁰。协调Al的较高分数_Ⅵ上的γ-Al ₂ ö ₃提供了用于吸附HCHO和形成中间体的多个相邻的羟基基团。OH基团的协同作用和对较小的Ag ⁰颗粒的高氧激活能力赋予了对Ag /γ-Al较高的HCHO氧化活性₂ O ₃（T ₁₀₀  = 85°C）。