王军,李文钊,张盈珍,于春英.还原气氛下金属-半导体催化体系Pt/MoO_3和Pt/Co_3O_4中电荷和物种传递特性的研究[J].分子催化编辑部,1996,(4):
还原气氛下金属-半导体催化体系Pt/MoO_3和Pt/Co_3O_4中电荷和物种传递特性的研究
Comparison of the Features of Charge and Species Transfer under Reductive Atmosphere between Two Kinds of Metal-Semiconductor Catalysts: Pt/MoO_3 and Pt/Co_3O_4
  
DOI:
中文关键词:  电导,程序升温还原,Pt/MoO_3,Pt/Co_3O_4
英文关键词:Semiconductivity, TPR, Pt/MoO_3, Pt/Co_3O_4
基金项目:
王军  李文钊  张盈珍  于春英
中国科学院大连化学物理研究所
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中文摘要:
      利用程序升温电导法(TPEC)和程序升温还原法(TPR),研究比较了还原气氛下Pt/MoO_3和Pt/Co_3O_4体系中不同类型的半导体氧化物和吸附氢之间电荷和物种交换的规律.发现微量Pt通过吸附解离H_2成为原子氢,在较低温度下大大加快n型半导体氧化物MoO_3和氢之间电子传递速度,显著地降低MoO_3的还原温度,但在同样条件下却不能有效地活跃p型半导体氧化物Co_3O_4和氢之间的电子传递,因而不能明显地促进Co_3O_4的还原.导致此现象的原因,可能与不同类型的半导体导电机构不同而引起的对氢的敏感程度不同有密切关系.
英文摘要:
      Different features of charge and species exchange between different kinds of semiconductors and adsorbed hydrogen on Pt/MoO3 and Pt/Co3O4 catalysts in hydrogen atmosphere were studied by temperature programmed electronic conductivity and temperature programmed reduction techniques. It was found on Pt/MoO3 that, very slight amount of Pt accelerated electron transportation between ntype semiconductor MoO3 and adsorbed hydrogen at very low temperature during TPEC, and thus greatly facilitated the reduction of MoO3, through adsorption and dissociation, H2spilt into atomic hydrogen. In contrast, it was shown on Pt/Co3O4 that, under the same condition as Pt/MoO3, electron exchange between p-type semiconductor Co3O4 and adsorbed hydrogen somewhat resembled that on pure Co3O4 at low temperature in spite of the existence of Pt as indicated by TPEC results, and thus the reduction of Co3O4was not speeded evidently by Pt. These phenomena are probably due to the different type of semiconductivity of MoO3and Co3O4.
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