Highly active spinel type CoCr2O4 catalysts for dichloromethane oxidation
Highly active spinel type CoCr2O4 catalysts for dichloromethane oxidation
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DOI：
10.1016/j.apcatb.2014.10.044
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发表时间：
2015-04
影响因子：
22.1
通讯作者：
Yu Wang;Ai-Pin Jia;M. Luo;Jiqing Lu
中科院分区：
文献类型：
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作者：
Yu Wang;Ai-Pin Jia;M. Luo;Jiqing Lu
制备了一系列经不同温度焙烧的尖晶石型CoCr2O4催化剂，并对二氯甲烷(CH2Cl2)的氧化反应进行了研究。这些催化剂对该反应具有一定的催化活性。反应最终产物为COX、HCl和Cl2，不生成含氯有机物。在400℃焙烧的催化剂(CoCr2O4-4)的催化性能最好，T50为218℃，T90为257℃，这主要是由于该催化剂具有最高的比表面积(91.3万m2g−1)。详细的定量分析表明，催化剂的表面酸性和还原能力共同控制了催化剂的催化行为，氨气程序升温脱附和氢气程序升温还原结果分别证明了这一点。动力学研究表明，这些催化剂具有相似的活化能(124.5-155.5 kJ·−-1)，这意味着反应可能遵循相同的路径。更重要的是，反应的原位傅里叶变换红外光谱研究表明，甲酸盐物种是主要的反应中间产物，可以进一步氧化成CO和CO2。
A series of spinel type CoCr2O4catalysts calcined at different temperatures were prepared and tested for oxidation of dichloromethane (CH2Cl2). These catalysts were active for this reaction. The final products in the reaction were COx, HCl and Cl2, without the formation of Cl-containing organics. The best performance was obtained on a catalyst calcined at 400 °C (CoCr2O4-4), with aT50of 218 °C and aT90of 257 °C, which was mainly due to the highest surface area of this catalyst (91.3 m2g−1). Detailed quantitative analyses revealed that the catalytic behavior was synergistically governed by surface acidity and reducibility of the catalyst, as evidenced by ammonia temperature-programmed desorption and hydrogen temperature-programmed reduction results, respectively. Kinetic studies revealed similar activation energies (124.5–155.5 kJ mol−1) on these catalysts, implying the reaction might follow the same pathways on these catalysts. More importantly, in situ Fourier transform infrared spectroscopic investigation of the reaction revealed that formate species were the main reaction intermediates, which could be further oxidized to CO and CO2.