摘要
本研究通过水热合成法并结合表面浸渍过程制备了Co_(3)O_(4)/WO_(3)复合催化剂,采用X射线衍射(XRD)、扫描电镜(SEM)、X射线光电子能谱(XPS)、透射电镜(TEM)、紫外-可见吸收光谱等测试技术对Co_(3)O_(4)/WO_(3)复合物的结构组成与微观形貌进行系统表征,在室温可见光照射下研究了Co_(3)O_(4)/WO_(3)对甲烷转化制甲醇的催化性能。结果表明,复合Co_(3)O_(4)可显著提升甲烷光催化转化性能,最优催化剂3.0%Co_(3)O_(4)/WO_(3)在可见光照射2 h时的甲烷转化量为2041μmol/g,对应的甲醇产生量及其选择性为1194μmol/g和58.5%,分别为单一WO_(3)的4.03倍和2.39倍,优于多数文献报道的甲烷转化异相光催化剂,且具有良好的循环稳定性。结合瞬态光电流与电子顺磁共振测试结果,揭示了引入Co_(3)O_(4)增强复合催化剂甲烷转化性能的内在机理,对设计光驱动甲烷转化制甲醇催化剂具有重要理论指导意义。
Direct and selective conversion of methane to methanol under mild conditions still faces grand challenges. In this study, Co_(3)O_(4)/WO_(3)nanocomposite catalysts were synthesized by facile hydrothermal method,combining with surface impregnation process. The structural composition and micro morphology of Co_(3)O_(4)/WO_(3)composites were characterized by X-ray diffraction(XRD), scanning electron microscopy(SEM), X-ray photoelectron spectroscopy(XPS), transmission electron microscopy(TEM) and UV-visible absorption spectrum.The catalytic performance of Co_(3)O_(4)/WO_(3)on the conversion of methane to methanol was investigated under visible light illumination at room temperature. The results show that incorporating Co_(3)O_(4)can remarkably improve the photocatalytic performance of methane conversion. The optimal catalyst 3.0% Co_(3)O_(4)/WO_(3)exhibits a methane conversion of 2041 μmol/g after visible light irradiation for 2 h, and the according methanol productivity and selectivity reach 1194 μmol/g and 58.5%, which are 4.03 and 2.39 times of single WO_(3)respectively. This performance is superior to most reported heterogeneous photocatalysts for methane conversion, meanwhile possessing excellent cyclic stability. Combining the results of transient photocurrent and electron paramagnetic resonance(EPR) with the catalytic activity, the intrinsic mechanism of enhanced methane conversion via introducing Co_(3)O_(4)is revealed, which is of theoretical significance to design light-driven catalysts for methane conversion to methanol.
作者
杨娟
陈鹏宇
戴俊
荣丽青
王大钊
YANG Juan;CHEN Peng-yu;DAI Jun;RONG Li-qing;WANG Da-zhao(School of Safety Science and Engineering,Henan Polytechnic University,Jiaozuo 454003,China;State Collaborative Innovation Center of Coal Work Safety and Clean-efficiency Utilization,Jiaozuo 454003,China;School of Chemistry and Chemical Engineering,Henan Polytechnic University,Jiaozuo 454003,China)
出处
《燃料化学学报》
EI
CAS
CSCD
北大核心
2022年第4期464-473,共10页
Journal of Fuel Chemistry and Technology
基金
国家自然科学基金(52074103)
河南省自然科学基金(202300410181)
河南省高等学校重点科研项目(21A440008)资助。
