Yolk-like Pt nanoparticles as cathode catalysts for low-Pt-loading proton-exchange membrane fuel cells

Long-Range Regulation of Se Doping for Oxygen Reduction of Atomically Dispersed Sb Catalysts for Ultralow-Temperature Solid-State Zn–Air Batteries

“…The excellent ORR activity of Sb–SeNC was further confirmed by the low Tafel slope of 69.4 mV dec –1 , which is smaller than those of Pt/C (75.2 mV dec –1 ), Sb–NC (81.4 mV dec –1 ), and Se–NC (81.6 mV dec –1 , Figure c). Figures d and S14 show that the electrochemical active surface area (ECSA) of Sb–SeNC is 38.2 mF cm –1 , higher than those of Sb–NC (35.5 mF cm –1 ) and Se–NC (28.5 mF cm –1 ), indicating that abundant pore structures in Sb–SeNC can expose more active sites . The HO 2 – yield of Sb–SeNC was smaller than 4% in the range of 0.2–0.8 V (Figure e) and was almost the same with 20% Pt/C in the range of 0.4–0.8 V. In addition, the average transfer electron number of Sb–SeNC is 3.92 in this voltage range (Figure e), which is close to the 4e – reaction pathway and consistent with the results calculated by the K–L equation (Figure S15).…”

“…Interestingly, Sb–SeNC also exhibits an apparently larger BET SSA (1738 m 2 g –1 ) than Sb–NC (1188 m 2 g –1 ) and Se–NC (1251 m 2 g –1 , Figure f), accompanying abundant micropores, mesopores, and macropores (Figures g and S8), which is attributed to the two-step pyrolysis of Sb–SeNC, while it is one-step pyrolysis for both Sb–NC and Se–NC. Two-step pyrolysis is beneficial for the formation of hierarchical porous structures that expose more active sites and facilitate mass transport in ORR. , The X-ray diffractions (XRDs) in Figure S9 also show that all three samples only present two broad peaks at around 25 and 44°, indicating the absence of Sb and Se nanoparticles (NPs) and their compounds. − …”

“…However, its PPD and stability still show a large gap for practical application. Therefore, developing highly efficient atomically dispersed catalysts with high specific surface area (SSA) , is key to achieving high-performance LT-ZAB.…”

Facile synthesis of Fe2P/Co embedded trifunctional electrocatalyst for high-performance anion exchange membrane fuel cells, rechargeable Zn–air batteries, and overall water splitting

“…S24†), which greatly weakens the adsorption of oxygen species for Fe 2 P at the interface. 58 Therefore, the ORR catalytic activity was greatly improved to 0.768 V for Fe 2 P(111)–Co(111) heterojunctions, demonstrating the synergistic effects between Fe 2 P and Co nanoparticles that could weaken the adsorption of oxygen species, and thereby effectively improves the ORR performance.…”

Ruthenium nanoparticles supported on Ni3N nanosheets as bifunctional electrocatalysts for hydrogen oxidation/evolution reactions

“…[2][3][4][5][6] Since the highly stable hydroxide exchange membrane was reported, 7 anionexchange membrane fuel cells (AEMFCs) have attracted much attention because they provide the possibility to use low-cost non-noble metal catalysts for alkaline ORR. Unfortunately, HOR (hydrogen oxidation reaction) catalysts are still the bottleneck that hinders the applications of AEMFCs, [8][9][10][11] because the HOR at the anode in an alkaline environment is two orders of magnitude slower than that in acid, and Pt-based materials are still needed as the catalysts. Therefore, the design of lowcost Pt-free catalysts for the alkaline HOR is important and urgently required.…”