| 过渡金属改性的Pd/TS-1催化氢、氧直接合成H2O2的性能 |
| Performance of Transition Metal Modified Pd/TS-1 in Direct Synthesis of Hydrogen Peroxide from H2 and O2 |
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| 摘要: 利用等体积浸渍法制备了M-Pd/TS-1(M=Ce，La，Pt，Fe，Co，Ni，Cr，Mn，Zn，Cd，Cu)系列催化剂，并将制得的催化剂用于常压下氢、氧直接合成过氧化氢的反应。考察了M的类型及负载量对M-Pd/TS-1催化剂催化性能的影响。结果表明，M选Ce时，催化剂的性能最好。Ce的最佳掺入量，nCe/(nCe+nPd)=0.5%。对Ce改性与未改性的催化剂进行了TEM及静态化学吸附分析，结果表明，掺入Ce可使Pd在TS-1分子筛表面的粒度及分散度得到改善。考察了nO2/nH2比，气体流量，反应时间等反应条件对H2转化率、H2O2选择性及收率的影响。在相对优化的工艺条件下，即nO2/nH2=3，气体流量为25 mL·min-1，反应时间为3 h时，H2O2的收率可达到25.7%，TOF值为18.7 mol·mol-1·h-1，此时溶液中H2O2的质量百分数为0.8%。 |
| 关键词: 钛硅分子筛 Pd催化剂 过渡金属 过氧化氢 直接合成 |
| 基金项目: |
| Abstract: M-Pd/TS-1(M=Ce, La, Pt, Fe, Co, Ni, Cr, Mn, Zn, Cd, Cu) catalysts were prepared by incipient wetness impregnation and their performance was evaluated for the direct synthesis of hydrogen peroxide from hydrogen and oxygen at atmospheric pressure. The effect of transition metal and the doping amount were studied on the activity of M-Pd/TS-1 catalyst. The catalysis evaluation results show that M-Pd/TS-1 catalyst doped with cerium significantly enhances the catalytic activity and the optimal molar ratio of Ce/(Ce+Pd) is 0.5%. The Ce-Pd/TS-1 and Pd/TS-1 catalysts were characterized by transmission electron microscopy(TEM) and chemical adsorption. The results indicate that the catalyst doped with cerium can improve the dispersivity of Pd on the surface of the TS-1 support and decrease the Pd particle size effectively. The influence of factors on H2 conversion and H2O2 yield were examined such as nO2/nH2 molar ratio, gas flow rate and reaction time. The yield of H2O2, the mass percentage of H2O2 and turn-over frequency(TOF) are up to 25.7%, 0.8% and 18.7 mol·mol-1·h-1, respectively, after 3 h reaction at nO2/nH2 of 3 with 25 mL·min-1 gas flow rate. |
| Keywords: titanium silicalite zeolite palladium catalyst transition metal hydrogen peroxide direct synthesis |
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| 安红强,王桂赟,王延吉,赵新强.过渡金属改性的Pd/TS-1催化氢、氧直接合成H2O2的性能[J].无机化学学报,2010,26(3):405-412. |
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