Atomically dispersed iron sites on a multi-shelled hollow structure for highly efficient CO2 fixation

Abstract

Gradually releasing reactants within a heterogeneous catalysis system is crucial to promote catalytic performance. Multi-shelled hollow structures (MHSs) possessing multi-functional pores have been considered a novel category of catalysts to accomplish the aforementioned goal. Herein, an innovative strategy is proposed for the stepwise construction of hierarchical MHSs to subtly introduce well-dispersed single-atom active sites on the MHS framework, namely, Fe/MHS. Benefiting from its enlarged active surface area, facile mass transfer capabilities, and sequential release of reactants (SR), Fe/MHS demonstrates high efficiency in promoting the conversion of CO₂ and maintaining stability. Experimental results and theoretical calculations reveal that the single atom Fe site rationally modulates the electron density profile, thereby decreasing activation energy and lowering the ring-opening energetic barrier during catalysis. Notably, our work not only developed an innovative strategy for catalyst fabrication but also provided novel perspectives for heterogeneous catalytic processes.