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本文采用TPR(Temperature Programmed Reduction)作为主要表征手段,对担载铜、镍催化剂循环还原-氧化(RedoX过程)处理前后的样品进行了表征.其次也进行了TPR测试后所得金属铜(镍)催化剂催化还原其前体氧化物(auto-catalysed reduction)的研究.发现这两种研究方式所得种种有趣结果都可归属于氢溢流现象.RedoX处理后,其TPR谱上金属氧化物的还原峰向低温区位移,并伴有总耗氢量的增加.其中峰位移可归属于Redox过程未被氧化完全的还原态金属(特别是铜)离解氢分子,形成的氢原子溢向邻近的金属氧化物(如CuO),使其在较低温度下还原;而耗氢量的增加则可归属氢原子向载体(SiO_2或Al_2O_3)的溢流,载体被活化使总耗氢量增加.上述现象可认为是同一颗粒间的氢溢流.在自催化还原过程中出现的氢溢流现象(低温区出现新还原峰和总耗氢量增加)可认为是催化剂不同颗粒间的氢溢流.总之TPR可以作为研究同一颗粒和不同颗粒间发生氢溢流行之有效的方法.
In this paper, TPR (Temperature Programmed Reduction) was used as the main characterization method to characterize the samples before and after the cyclic reduction-oxidation (RedoX process) of supported copper and nickel catalysts.Secondly, the metal copper (nickel) catalyst Catalytic reduction of its precursor-oxide (auto-catalysed reduction) study found that the results of these two kinds of research results are attributable to the phenomenon of hydrogen overflow .RedoX treatment, the TPR spectrum reduction peak of the metal oxide With the increase of total hydrogen consumption, the peak shift can be attributed to that the redox process is not completely oxidized by the reduced metal (especially copper) to dissociate the hydrogen molecules, and the hydrogen atoms are formed to overflow to the adjacent metal oxide (Such as CuO) to reduce at lower temperature, while the increase of hydrogen consumption can be attributed to the overflow of hydrogen atoms to the support (SiO_2 or Al_2O_3), and the support is activated to increase the total hydrogen consumption. Is the hydrogen overflow between the same particles.The phenomenon of hydrogen overflow during autocatalytic reduction (new reduction peak in the low temperature zone and increase of the total hydrogen consumption) can be considered as the hydrogen overflow between different particles of the catalyst. As a method effective to hydrogen spillover occurs between the same particles and different particles are investigated.