Abstract
The intriguing features of single-atom catalysts (SACs) could bring catalysis into a new paradigm, however, controllably synthesising SACs with desired SA loadings and coordination forms are challenging. Here, we report an adsorption-regulated approach to precisely control the synthesis of bimetallic Fe-Co SAs on carbon. Bacterial cellulose (BC) is utilised as an adsorption regulator to controllably impregnate Fe3+/Co2+ on BC and through carbonisation to anchor Fe-Co SAs on BC-derived carbon via bimetallic [(O-C2)3Fe-Co(O-C2)3] coordination with desired Fe/Co contents and atomic ratios. Under electrocatalytic nitrogen reduction reaction (NRR) conditions, [(O-C2)3Fe-Co(O-C2)3] is operando transformed to [(O-C2)3Fe-Co(O-C)C2] that promotes and sustains NRR performance. A superb ammonia yield of 574.8 ± 35.3 μg h-1 mgcat.-1 with an exceptional faradaic efficiency of 73.2 ± 4.6% are obtained from an electrocatalyst with the highest bimetallic Fe-Co site density. The exemplified synthetic approach would be of generically applicable to controllably anchor SAs on carbon that enables meaningfully investigate and rationally design SACs.
Adsorption-regulated precise synthesis of atomically-dispersed bimetallic Fe-Co sites on carbon for electrocatalytic nitrogen reduction reaction
