水热合成Co_3O_4的制备参数调变及其催化分解N_2O性能（英文）

Effect of preparation parameters on the catalytic performance of hydrothermally synthesized Co_3O_4 in the decomposition of N_2O

以十六烷基三甲基溴化胺(CTAB)为模板剂,通过调变CTAB浓度水热合成了氧化钴前驱体,焙烧制得棒状形貌的Co_3O_4,在其表面浸渍K_2CO_3溶液制得K改性的Co_3O_4催化剂,用于N_2O分解。用X射线衍射(XRD)、N_2物理吸附(BET)、扫描电镜(SEM)、X射线光电子能谱(XPS)、H_2程序升温还原(H_2-TPR)和O_2程序升温脱附(O_2-TPD)等技术对催化剂进行了表征,考察了CTAB/钴及尿素/钴物质的量比等制备参数对Co_3O_4催化分解N_2O活性的影响。结果表明,CTAB浓度为0.05 mol/L、CTAB/钴离子物质的量比为1、尿素/钴离子物质的量比为4时,所制备的Co_3O_4催化剂具有较高的N_2O分解活性,而K改性可以进一步提升其催化性能。K改性的Co_3O_4在有氧有水气氛中400℃下进行N_2O分解反应,50 h后N_2O转化率仍保持在91%以上。

With hexadecyl trimethyl ammonium bromide（ CTAB） as the template,cobaltosic oxide precursors were hydrothermally synthesized. Co3O4 catalysts were then prepared by calcining the cobaltosic oxide precursors,which was further modified by impregnation with K2CO3 solution and used in the decomposition of N2O. The catalysts were characterized by means of X-ray diffraction（ XRD）,nitrogen physisorption,scanning electron microscopy（ SEM）,X-ray photoelectron spectroscopy（ XPS）,hydrogen temperature-programmed reduction（ H2-TPR）,and oxygen temperature-programmed desorption（ O2-TPD）; the effect of CTAB concentration,CTAB/cobalt molar ratio and urea/cobalt molar ratio on the catalytic activity of Co3O4 was investigated. The results indicated that the Co3O4 catalyst prepared by using 0.05 mol/L CTAB solution,with a CTAB to cobalt molar ratio of 1 and a urea to cobalt molar ratio of 4,exhibits high activity in N2O decomposition. The catalytic performance of Co3O4 can be further enhanced by modifying with K. Over the 0.02 K/Co3O4 catalyst,the N2O conversion remains over 91% at 400 ℃ after conducting the N2O decomposition reaction for 50 h in the presence of oxygen and steam.