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采用溶胶凝胶法制备 Co Mo O4 催化剂, 经 K 助化后分别在空气中于400~800 ℃下进行焙烧, 得到氧化态样品, 然后经硫化制得硫化态 K Co Mo 催化剂, 对氧化态样品的乙醇分解性能及硫化态样品的 C O 加氢合成低碳醇的反应性能进行了测试. 运用 X 射线衍射( X R D )和扩展 X光吸收精细结构( E X A F S )对样品进行结构表征. 乙醇分解性能测试表明, 催化剂的表面酸性较弱, 且随着焙烧温度的升高变化不大. 合成醇性能测试结果则显示, 催化剂的焙烧温度升高后,其合成醇的产率逐步降低, 但醇选择性基本不变. 经 400 ℃焙烧的样品, 具有最好的催化活性.结构分析结果表明, 氧化态样品中存在多种 K M o O 物种, 且随着焙烧温度的提高, 钾钼之间作用增强, 样品更难以被完全硫化.
The Co-MoO4 catalyst was prepared by sol-gel method and calcined at 400-800 ℃ in air after being boiled by K to obtain an oxidized state sample, and then the sulfided K-Co-Mo catalyst was obtained through sulfidation The ethanol decomposition performance of the oxidized samples and the reactivity of the C O hydrogenation of the sulfated samples to the synthesis of the lower alcohols were tested. The samples were characterized by X-ray diffraction (XRD) and extended X-ray absorption fine structure (E X A F S). Ethanol decomposition performance tests showed that the surface acidity of the catalyst is weak, and with the calcination temperature did not change much. The result of the test of the synthetic alcohol shows that the yield of the synthetic alcohol gradually decreases after the calcination temperature of the catalyst increases, but the alcohol selectivity is basically unchanged. The sample calcined at 400 ℃ has the best catalytic activity. The results of structural analysis show that there are many KMoO species in the oxidized samples. With the increase of calcination temperature, the interaction between potassium and molybdenum is enhanced, and the samples are more difficult to be completely sulfided.