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采用等体积浸渍法制得过渡金属改性的系列催化剂MO x-PdO/γ-Al2O3(M=La、Mn、Ni、Ce)。在10℃、常压下考察了过渡金属种类及氧化镧负载量对催化剂MO x-PdO/γ-Al2O3催化氢氧直接合成过氧化氢性能的影响。采用能谱(EDS)、X射线衍射(XRD)、程序升温还原(H2-TPR)等手段对催化剂进行表征分析。结果表明,经过渡金属改性后的MO x-PdO/γ-Al2O3催化剂活性高于未改性的催化剂PdO/γ-Al2O3;以镧为助剂制得的La2O3-PdO/γ-Al2O3(氧化镧质量分数为1%、氧化钯质量分数为2.5%)催化剂性能优于其他过渡金属改性的催化剂,与PdO/γ-Al2O3相比,所得过氧化氢的浓度、收率、选择性分别提高了76.54%、76.61%、44.21%。
The transition metal modified catalysts MO x -PdO / γ-Al 2 O 3 (M = La, Mn, Ni, Ce) were prepared by the same volume impregnation method. The effects of transition metal species and lanthanum oxide loading on the performance of hydrogen peroxide catalyzed by MO x-PdO / γ-Al2O3 catalyst were investigated at 10 ℃ and atmospheric pressure. The catalysts were characterized by EDS, X-ray diffraction (XRD) and temperature-programmed reduction (H2-TPR). The results show that the activity of MO x -PdO / γ-Al2O3 modified by transition metal is higher than that of unmodified PdO / γ-Al 2 O 3; La 2 O 3 -PdO / γ-Al 2 O 3 The content of lanthanum is 1%, the mass fraction of palladium oxide is 2.5%), the catalyst performance is better than that of other transition metal-modified catalysts. The concentration, yield and selectivity of hydrogen peroxide are higher than that of PdO / γ-Al2O3 76.54%, 76.61%, 44.21%.