Mei Ji, Shen Yao, Wang Qiaoli, Shen Yi, Li Wei, Zhao Jingkai, Chen Jianrong, Zhang Shihan
College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, China.
Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou 310014, China.
ACS Appl Mater Interfaces. 2022 Aug 10;14(31):35694-35703. doi: 10.1021/acsami.2c08418. Epub 2022 Jul 29.
To realize efficient low-temperature catalytic -xylene oxidation, MOF-derived CeO-X catalysts were prepared via the pyrolysis of MOF precursors with different ratios of cerium nitrate to trimesic acid. Among the synthesized catalysts, the bouquet like CeO-1 exhibited the best activity with and of 156 and 198 °C and the lowest activation energy of 60.67 kJ·mol (WHSV= 48 000 mL·g·h, -xylene concentration = 500 ppm). -Xylene was completely mineralized, and no change in conversion efficiency or CO yield was found at 5 vol % HO for over 50 h. The rich active oxygen species (XPS: O/O = 0.69) and abundant oxygen vacancies (Raman: / = 0.036) of CeO-1 made crucial contribution to its superior catalytic activity. The O-TPD and H-TPR results confirmed that CeO-1 had more surface active oxygen and better mobility of bulk oxygen. Moreover, the reaction routes under different atmospheres were probed through DRIFTS, in which oxygen vacancy played a key role in promoting the adsorption and activation of molecular oxygen and facilitating the migration of the bulk lattice oxygen.
为实现高效的低温催化二甲苯氧化，通过对硝酸铈与均苯三甲酸比例不同的MOF前驱体进行热解，制备了MOF衍生的CeO-X催化剂。在合成的催化剂中，花束状的CeO-1表现出最佳活性，T10和T90分别为156和198 °C，最低活化能为60.67 kJ·mol（WHSV = 48000 mL·g·h，二甲苯浓度 = 500 ppm）。二甲苯完全矿化，在5 vol% H2O存在下超过50小时，转化率或CO产率未发现变化。CeO-1丰富的活性氧物种（XPS：O2−/O− = 0.69）和大量氧空位（拉曼：F2/F1 = 0.036）对其优异的催化活性起到了关键作用。O-TPD和H-TPR结果证实，CeO-1具有更多的表面活性氧和更好的体相氧迁移率。此外，通过漫反射红外傅里叶变换光谱（DRIFTS）探究了不同气氛下的反应路径，其中氧空位在促进分子氧的吸附和活化以及促进体相晶格氧的迁移方面起关键作用。
