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本文用Perkin-Elmer FTIR 1710型红外光谱仪,对Cu-Co-Fe系合成混合醇催化剂进行研究。实验发现,催化剂在氧化态的物相分别以CuO、Co_3O_4和α-Fe_2O_3形式存在,这与X-射线衍射结果一致。由于组分间的相互作用,某些特征红外吸收峰有红移现象,CuO和α-Fe_2O_3的红外峰向低波数位移,使得Cu—O键和Fe—O键被削弱,因而催化剂更容易被还原。通过考察CO在还原态催化剂上的吸附行为,发现低温下CO吸附时,红外谱图上没有新的吸收峰;高温下吸附时在2135cm~(-1)和1745cm~(-1)附近存在有明显的吸收峰;前者归结为不可逆线式吸附,后者为桥式吸附结构;支持了在铁系催化剂上CO/H_2合成醇过程的链增长机理假设。铁组分的存在,有利于桥式结构的形式。
In this paper, Perkin-Elmer FTIR 1710 infrared spectrometer was used to study the Cu-Co-Fe synthetic mixed alcohol catalyst. It was found that the phases of catalysts in the oxidation state were in the form of CuO, Co_3O_4 and α-Fe_2O_3 respectively, which was consistent with the results of X-ray diffraction. Because of the interaction between the components, some of the characteristic infrared absorption peaks have a red shift phenomenon. The infrared peaks of CuO and α-Fe_2O_3 shift to low wavenumbers, so that Cu-O and Fe-O bonds are weakened, thus the catalyst is more easily reduction. By observing the adsorption behavior of CO on the reduced catalyst, it was found that there was no new absorption peak on the infrared spectrum when the CO was adsorbed at low temperature. At high temperature, the adsorption was near 2135cm -1 and 1745cm -1 The former is attributed to the irreversible linear adsorption and the latter to the bridge adsorption structure. It supports the hypothesis of chain growth mechanism of CO / H 2 synthesis on the iron-based catalyst. The presence of iron components favors the form of bridge structure.