電化學觸媒結晶暴露面的改質被認為是改良其物理及化學性質並優化觸媒材料電化學活性之策略。在這裡，我們初次報導了Co3O4晶體暴露面對於電化學甘油氧化反應影響的完整實驗分析。我們的研究是透過水熱法的方式製備兩種不同暴露晶面 的尖晶石Co3O4，分別是控制生長晶面為{100}(形態學為正立方體)的cube Co3O4(C-Co3O4)以及控制生長晶面為{111}(形態學為八面體)的octahedron Co3O4(O-Co3O4)，並發現兩著相比O-Co3O4有著更好的甘油電催化甘油氧化表現，O-Co3O4 (平均電流0.295 mA/cm2) 相比於C-Co3O4 (平均電流0.149 mA/cm2)有著更高的電流密度，且在高經濟價值產物二羥基丙酮(DHA)的選擇率以及產量上O-Co3O4也都有較好的表現。本研究發現，甘油的吸附是造成{111}暴露晶面之產物選擇率的關鍵因素，且揭曉O-Co3O4的電荷轉移阻抗較小，有效促進電荷的轉移，增強甘油氧化和電化學活性。

The modification of the exposed surface of the electrochemical catalyst crystal is considered as a strategy to improve its physical and chemical properties and optimize the electrochemical activity of the catalyst material. Here, we report for the first time a complete experimental analysis of the effect of exposed facets of Co3O4 crystals on glycerol electro- oxidation. In our research, we prepare two kinds of spinel Co3O4 with two different exposed facets by hydrothermal method, i.e. controlled growth crystals of {100}-oriented Cube Co3O4 (C-Co3O4) with cube morphology and controlled growth crystals of {111}-oriented Octahedron Co3O4 (O-Co3O4) with octahedral morphology. We found that O-Co3O4 have better glycerol glycerol electro-oxidation performance than C-Co3O4, and O-Co3O4 (average current density: 0.295 mA/cm2) has a higher current density than C-Co3O4 (average current density: 0.149 mA/cm2). Additionally, O-Co3O4 also produce a higher yield and little higher selectivity on high valuable dihydroxyacetone (DHA) products. In this study, it was found that the adsorption of glycerol was a key factor in the glycerol electrooxidation reaction product selectivity of the {111} exposed facets, and it was revealed that O-Co3O4 has a smaller charge transfer resistance, which effectively promoted the charge transfer, resulting in the enhancement of glycerol oxidation and electrochemical activity.

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