海胆状CoCu双金属纳米复合材料的合成及其在甘油氢解制丙二醇中的催化性能

Urchin-like CoCu Bimetallic Nanocomposites for Catalytic Hydrogenolysis of Glycerol to Propanediols

以Ru为多相成核剂和硬脂酸为表面活性剂，在多元醇溶液中合成了CoCu双金属纳米复合物，并在甘油选择性氢解制丙二醇中评价了其催化性能．结果表明，硬脂酸作为结构导向剂可诱使Co纳米晶沿着一维方向生长，形成纳米线．当CO2＋和Cu2＋共存于多元醇溶液中，由于Cu2＋较高的氧化还原电位，首先被还原成Cu0，进而增长成100-300am的球形粒子．在Cu粒子表面，CO2＋被还原成核，在表面活性剂的结构导向作用下生长为长度为100-500am的纳米棒，从而形成海胆状CoCu双金属纳米复合结构．在甘油选择性氢解制丙二醇反应中，海胆状CoCu双金属复合催化剂的单位表面活性与丙二醇选择性均明显高于单金属Co纳米线和Cu球形粒子，在C090Cu10催化剂上获得33％的丙二醇收率．这可能是由于Co和Cu界面的协同效应促进了甘油的转化所致．

Bimetallic CoCu nanocomposites were synthesized in polyol by using Ru as heterogeneous nucleation agent and stearic acid as surfactant, and their catalytic properties were investi- gated by hydrogenolysis of glycerol to propanediols. It was found that the surfactant could induce Co nanocrystals to form nanowires as structure-directing agent, while it＇s ineffective for Cu because only spherical Cu particles were produced under the same condition. When Co2＋ and Cu2＋ coexist in polyol, Cu2＋ is firstly reduced and forms the spherical particles, and then the Cu particles afford surface for the subsequential reduction of Co2＋ and growth of Co nanocrystals to form the nanorods, obtaining the urchin-like CoCu nanocomposites. The catalytic performance in selective hydrogenolysis of glycerol to propanediols proposed that the CoCu urchin-like nanocomposites was superior to the Co nanowires possibly due to that the synergistic effect between Co and Cu component promoted conversion of glyc- erol and obtained the higher propanediol yields based on the specific surface areas of the catalysts.