摘要
本工作以2-甲基咪唑、六水合硝酸锌及乙酰丙酮钴为前驱体,通过溶剂热反应合成出基于金属有机框架材料的Co@ZIF-8,经高温热解还原,成功制备出以Co-Nx为活性位点的氮掺杂碳限域Co催化剂(Co@ZIF-8(C)).采用扫描电子显微镜、透射电子显微镜、X射线衍射分析、X射线光电子能谱、拉曼光谱、电感耦合等离子发射光谱仪、傅里叶变换红外光谱仪和氮气吸脱附测试等对催化剂进行了系统表征.分析表明,合成的Co@ZIF-8(C)催化剂中的Co以原子簇的形式均匀分散在氮掺杂碳载体内,氮掺杂为锚定金属Co提供了位点,ZIF-8载体大的比表面积和介孔结构提高了底物与活性位点的接触机率.载体与金属之间的强相互作用和载体的空间限域效应,提高了Co原子簇对催化硝基化合物转移加氢的性能,使其在常温下实现了高转化率、循环稳定及底物通用等性能.
Development of non-precious metal hydrogenation catalysts under mild conditions is of great significance to modern chemical industry.In this work,Co@ZIF-8 based on metal-organic framework material was synthesized using 2-methylimidazole,zinc nitrate hexahydrate and cobalt acetylacetonate as precursors under solvothermal reaction condition at 120℃for 6 h.Nitrogen-doped carbon with spatial confinement effect of Co catalyst(Co@ZIF-8(C))with Co-Nx as active site was successfully prepared by high temperature pyrolytic reduction at 1000℃under nitrogen atmosphere.The catalyst was systematically characterized by scanning electron microscopy,transmission electron microscopy,X-ray diffraction,X-ray photoelectron spectroscopy,raman spectroscopy,inductively coupled plasma emission spectrometry,fourier transform infrared spectroscopy,and nitrogen adsorption and desorption test.The analysis showed that Co in the synthesized Co@ZIF-8(C)catalyst was uniformly dispersed as atomic clusters confined in nitrogen-doped carbon carrier with content 1.8%(w).The doping nitrogen provides sites for anchoring the metal Co to form Co-Nx sites.Large specific surface area and mesoporous structure of the ZIF-8 carrier increased contact probability between substrate and active site.Strong interaction between the carrier and metal and spatial confinement effect improved the performance of Co clusters for catalytic transfer hydrogenation of nitro compounds.When 10 mg catalyst,0.2 mmol nitrobenzene,0.8 mmol AB(NH3BH3),3 mL methanol and 2 mL deionized water as solvents were added to reaction system at 30℃,the yield of aniline could reach more than 99%after 10 min.Catalytic performance of this catalyst was better than that of ZIF-8(C),ZIF-67(C)and other Co catalysts re-cently reported.In addition,nitro compounds with different functional groups were also obtained in high yields under this system except for those with larger functional groups.Cycling and hot filtration experiments demonstrated that the Co cata-lyst has excellent stability and re
作者
周何鑫
崔青云
胡雪敏
杨文秀
田肖
王硕
Zhou Hexin;Cui Qingyun;Hu Xuemin;Yang Wenxiu;Tian Xiao;Wang Shuo(College of Chemical and Textile Engineering,Xinjiang University of Science and Technology,Korla 710025,China;Textile and Garment Technology Innovation Center,Hebei University of Science and Technology,Shijiazhuang 050018,China)
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
2024年第5期503-510,共8页
Acta Chimica Sinica
基金
河北省自然科学基金(No.B2021208001)
石家庄市重点研发计划(No.221070361A)
新疆高校基本科研业务费科研项目(No.XJEDU2023014)资助。
关键词
Co原子簇
金属有机框架
转移加氢
氨硼烷
硝基化合物
Co atom cluster
metal-organic framework
transfer hydrogenation
ammonia-borane
nitro compound
