Preparation of Fe single-atom carbon materials for DMFC and ZAB cathodic ORR catalysts based on the natural corn stalk binder/corn stalk biomass composite

To enhance the large-scale manufacture of zinc-air batteries (ZAB) and direct methanol fuel cells (DMFC), high-performance oxygen reduction reaction (ORR) catalysts must be developed. In this study, corn stalk binder (CS binder) was added to corn stalk (CS), the ratio between the two was adjusted, and the structure and morphology of the carbon material was altered to create a biocarbon substrate material (15 wt% N/C (CS)) with ORR catalytic activity. It had a half-wave potential (E1/2) that was 29 mV greater than the pure carbon substance from CS (0 wt% N/C(CS)). Using Fe and N coordination-Hemin, an iron single-atom catalyst (15 wt% FeN/C (CS)) was created based on this. Commercial Pt/C catalysts are anticipated to be replaced by the 15 wt% FeN/C (CS), which demonstrated exceptional peak power density in both DMFC and ZAB cell tests. The catalytic mechanism of 15 wt% FeN/C (CS) is explained by density functional theory (DFT), whereby the 15 wt% N/C (CS) carbon substrate rich in faulty structures creates space for the effective use of the iron single-atom reactive sites. Furthermore, the FeN sites reduced the overpotential of ORR, which promoted the adsorption and reduction of oxygen molecules at the active sites.