Multistep protection strategy for preparation of atomically dispersed Fe-N catalysts for selective oxidation of ethylbenzene to acetophenone

The fabrication of catalysts with atomically dispersed metal active sites is a hot research topic in catalysis, but the controllable preparation of single-atom catalysts still presents several challenges due to the aggregation tendency of active sites. Herein, an elaborate multistep protection strategy for the preparation of atomically dispersed Fe atoms on three-dimensional N-doped hollow carbon spheres was reported. Experimental results show that the pre-separation of 1,10-phenanthroline, the anchoring effect with N sites, and the three-dimensional hollow spherical structure of the support are crucial to achieving atomic dispersion of Fe atoms. The obtained single-atom catalysts, labeled as Fe-N@HCS-T (T represents the calcination temperature), were analyzed in detail. Fe-N@HCS-T exhibited excellent catalytic activity and selectivity for the oxidation of ethylbenzene under mild reaction conditions. Furthermore, the prepared catalysts exhibit excellent stability and recyclability. Therefore, this study is expected to provide a feasible strategy for the design of high-efficiency single-atom catalysts for future catalytic applications.