Co基催化剂在氢甲酰化反应中的应用研究进展

氢甲酰化反应是工业中重要的合成醛的过程。目前,氢甲酰化反应中使用的催化剂以Rh和Co基催化剂为主,其中Rh基催化剂主要应用于短链烯烃的氢甲酰化,中长链烯烃的氢甲酰化仍采用Co基催化剂。以Co基催化剂为主线,重点综述了均相和多相负载型Co基催化剂的制备及在氢甲酰化反应中的应用研究进展。分析表明,在均相Co基催化剂中引入给电子能力强、空间位阻大的烷膦配体有助于提高产品醛区域选择性并使反应条件变得更温和。在多相负载型Co基催化剂中,载体种类及性质、贵金属助剂、金属前驱体、配体及制备条件等均能对氢甲酰化反应催化性能产生影响。今后可以设计合成给电子能力强、空间位阻大的烷膦配体,将其负载于具有高比表面积、多级孔道结构的载体上或通过官能团修饰将配体多相化负载金属Co以提高其氢甲酰化反应催化性能。

NHC-Pd/NiFe_2O_4催化剂的制备及其催化Suzuki反应性能

由醇-水溶液加热法结合超临界流体干燥制备得到晶体结构完整、磁性良好、比表面积大的Ni Fe2O4并用其作为载体,通过简单的浸渍法制备NHC-Pd/Ni Fe2O4催化剂.NHC-Pd/Ni Fe2O4催化Suzuki反应表现出高活性和高循环稳定性.催化剂五次循环后活性没有明显降低.

Coordination environment of active sites and their effect on catalytic performance of heterogeneous catalysts

The structural complexity of supported metal catalysts,playing significant role in a wide range of chemical technologies,have prevented us from deeply understanding their catalytic mechanisms at atomic level.A fundamental understanding of the nature of active sites and structure–performance relationship of supported metal catalysts from a comprehensive view will open up numerous new opportunities for the development of advanced catalysts to address the global challenges in energy conversion and environmental protection.This review surveys the effects of multiple factors,including the metal size,shape,support,alloy and ligand modifier,on the coordinated environment of active center and further their influence on the catalytic reactions,aiming to provide guidance for the design of industrialized heterogeneous catalysts with extraordinary performance.Subsequently,the key structure characterization techniques in determining the coordination structure of active metal sites,especially the dynamic coordination structure change under the reaction condition,are well summarized.A brief summary is finally provided together with personal perspectives on the further development in the field of heterogeneous metal catalysts.