Ultrafine Ruthenium Clusters Shell‐Embedded Hollow Carbon Spheres as Nanoreactors for Channel Microenvironment‐Modulated Furfural Tandem Hydrogenation

Abstract Rationally modulating the catalytic microenvironment is important for targeted induction of specific molecular behaviors to fulfill complicated catalytic purposes. Herein, a metal pre‐chelating assisted assembly strategy is developed to facilely synthesize the hollow carbon spheres with ultrafine ruthenium clusters embedded in pore channels of the carbon shell (Ru@Shell‐HCSs), which can be employed as nanoreactors with preferred electronic and geometric catalytic microenvironments for the efficient tandem hydrogenation of biomass‐derived furfural toward 2‐methylfuran. The channel‐embedding structure is proved to confer the ultrafine ruthenium clusters with an electron‐deficient property via a reinforced interfacial charge transfer mechanism, which prompts the hydrogenolysis of intermediate furfuryl alcohol during the tandem reaction, thus resulting in an enhanced 2‐methylfuran generation. Meanwhile, lengthening the shell pore channel can offer reactant molecules with a prolonged diffusion path, and correspondingly a longer retention time in the channel, thereafter delivering an accelerated tandem hydrogenation progression. This paper aims to present a classic case that emphasizes the critical role of precisely controlling the catalytic microenvironment of the metal‐loaded hollow nanoreactors in coping with the arduous challenges from multifunctional catalyst‐driven complex tandem reactions.