摘要
CONSPECTUS:In heterogeneous catalysis,the long-standing challenge isto achieve extremely high activity and chemoselectivity in liquid-phaseorganic transformations comparable to that of homogeneous or enzymaticprocesses.Single-atom catalysts(SACs)with atomically precise coordinationare developed with the objectives to mimic the homogeneous pathwaysbut face stability issues due to metal leaching or clustering.Additionally,thepractical application of SACs in chemical production is hampered by thelack of standard preparation protocols and low conversion using laboratorybatch reactors.This Account focuses on our recent studies in both catalyst design andreactor-level engineering for the flow synthesis of fine chemicals via SACs.At the catalyst and reaction level,we will discuss the intrinsic mechanismthat controls reactivity and chemoselectivity in the SAC-catalyzed processand highlight examples where SACs outperform other catalytic approaches.Specifically,we reported the SAC-mediated preparationand late-stage functionalization of pharmaceutical drugs,including lonidamine,Tamiflu,cavosonstat,indomethacin,and many othersby chemoselective transformations in a sequential or multicomponent manner.The ability of ultrahigh loading SACs in providing amultisite pathway for organic transformations involving two or more reactants is highlighted and contrasted with the single-sitepathway in conventional SACs.Molecular-level understanding on the dynamic catalytic cycle obtained using operando X-rayabsorption spectroscopies provides guidance for the design of more effective and leach resistant SACs.This also calls for thetransformation of laboratory powder-based catalysts into industrially viable monolithic catalysts via formulation to further enhancethe leach resistance.At the reactor level,we will highlight the importance of continuous-flow techniques in maximizing productivityand simplifying process transfer from laboratory to commercial production.Particularly,we discuss the use of fuel cell-type flowstacks for quantitative pr
基金
NUS’s Centre for Hydrogen Innovation program CHI-P2022-01.
