A facile dual isolation and protection strategy for preparation of PtFe intermetallic compound in biomass-derived carbon with high activity and durability for pH-universal bifunctional electrocatalysts.

A facile dual isolation and protection strategy is developed to prepare PtFe intermetallic electrocatalyst (PtFe–N–C@bioC) on porous biomass carbon (bioC) derived from peanut shell. In preparation, meso-tetraphenylporphyrine (H 2 TPP) together with platinum (II)-tetraphenylporphyrin (PtTPP) are in-situ fabricated on the porous peanut shell-derived bioC matrixes and then further absorbed Fe (III) tetraphenyl porphyrin (FeTPP) molecules through π−π interactions between PtTPP/H 2 TPP and FeTPP to form a mixed precursor of FeTPP/PtTPP/TPP-bioC. Upon pyrolysis of FeTPP/PtTPP/TPP-bioC, PtFe bimetallic-containing N-doped carbon formed on bioC (PtFe–N–C@bioC). The resultant PtFe–N–C@bioC showed excellent oxygen reduction reaction (ORR) and hydrogen evolution reaction (HER) activity across a wide pH range. In particular, under alkaline medium, PtFe–N–C@bioC shows the ORR performance with an onset potential (E onset) of 0.989 V, a half-wave potential (E 1/2) of 0.901 V and a limiting current density (J L) of −6.214 mA cm−2. Meanwhile, PtFe–N–C@bioC delivers an enhanced mass activity (1.197 A mg−1 Pt), which is 13 times larger than commercial Pt/C. For HER, PtFe–N–C@bioC shows an impressive overpotential (η 10) of 17 mV at a current density of 10 mA cm−2 under acidic medium. Further, it is applied to Zn-Air batteries with a power density performance of 98.7 mW cm−2 and good durability. • A facile dual isolation and protection strategy is developed. • Highly efficient dispersion of PtFe intermetallic electrocatalyst is obtained. • The bio-derived PtFe–N–C@bioC catalysts exhibit high performance for ORR and HER. [ABSTRACT FROM AUTHOR]