In Situ Alloying with Hybrid Mesoporous Fe–N–C to Accelerate the Catalysis Efficiency of Pt for the Oxygen Reduction Reaction

Abstract

Pt-based intermetallic alloys with high activity and stability are promising for accelerating the cathodic oxygen reduction reaction (ORR) and large-scale application of proton exchange membrane fuel cells. So far, facile synthesis of Pt-based alloys in less time is desirable but still challenging. Herein, based on the traditional wet impregnation method, facile in situ reduction of H2PtCl6 and alloying with a hybrid nanostructure mainly doped with Fe single atoms as well as small amounts of Fe-based nanoparticles and oxides were developed to fabricate highly dispersed PtFe nanoparticles loaded on a mesoporous Fe–N–C support. Alloying of Pt derived from H2PtCl6 with various iron-based species existing in forms of single-atom, metallic, and oxide states was confirmed by systematic characterization, and the Fe content in the support is important for PtFe alloy formation, and the corresponding electrochemical performance promotion has been identified. The as-synthesized best-performance PtFe/Meso-PDA-5 catalyst delivered a high potential of 0.925 V at a current density of 3 mA cm–2 and achieved a high mass activity of 497.5 mA mgPt –1 at 0.9 V for the ORR in 0.1 M HClO4. More importantly, only 17.9% mass activity loss was observed after 10k potential cycles of the accelerated deterioration test. The present work provides a strategy for facile synthesis of Pt-based alloy nanomaterials for ORR catalysis and highlights the importance of supports in alloy formation.

Engineering PtCu Alloy Nanoparticles on ZIF-8-Derived N-Doped Carbon for Enhanced Oxygen Reduction Reaction

“…Therefore, the excellent ORR catalytic activity can be partially ascribed to the high-efficiency Pt utilization. The performance of PtCu/NC is comparable with the recently reported Pt-based catalysts in different studies. − Table S2 shows higher MA and better ORR performance of PtCu/NC compared to previously reported Pt alloy catalysts. ,,,− …”

“…The researchers have adopted various strategies, such as Pt alloying, interface engineering, , and local structural disorders, to improve the intrinsic activity of the Pt electrocatalysts by tuning its morphology, component, structure, and electronic structure. A particularly effective strategy for reducing the platinum content while keeping the ORR performance is to form an alloy between platinum and various transition metals such as Co, Fe, Cu, and Ni . Incorporating transition metals not only produces a lattice–strain effect and shortens the Pt–Pt bond but also brings the d-band center closer to the Fermi energy level, which can weaken the oxygen affinity, thus enhancing the ORR performance of the catalysts. , However, these bimetallic alloy catalysts eventually suffer from dissolution and aggregation of metal nanoparticles owing to the insufficient interaction between the alloy nanoparticles and carbon materials, leading to a decrease in catalytic activity.…”

Controlled Construction of Core‐Shell Structured Prussian Blue Analogues towards Enhanced Oxygen Reduction

“…Figure 3a shows the comparisons of XPS Fe 2p spectra for HMPB-1.3Mn, HMPB-2.6Mn and HMPB-3.9Mn, and the corresponding sub-bands with binding energy values at 708.81 eV, 711.3 eV, 721.67 eV, 724.32 eV and 717.33 eV can be attributed to Fe 2 + 2p 3/2 , Fe 3 + 2p 3/2 , Fe 2 + 2p 1/2 , Fe 3 + 2p 1/2 and the satellite peak, respectively. [17] As the Mn loading amount increases, the area ratio of Fe 2 + /Fe 3 + begin to increase, that is to say, the chemical valence of Fe in HMPBÀ Mn decreases gradually owing to the substitution Mn to Fe. The specific area ratios of Fe 2 + to Fe 3 + were displayed in Table S3.…”

Pt nanoparticles anchored by oxygen vacancies in MXenes for efficient electrocatalytic hydrogen evolution reaction

“…Generally, alloying and introducing carriers are two common strategies to disperse Pt nanoparticles, decrease the Pt nano-size and improve the utilization of Pt. 18–21 Compared with alloying, compositing suitable carriers with Pt could enhance the HER activity by migrating H atoms on the surface of metal nanoparticle catalysts to the reducible carrier. 22,23 This hydrogen spillover phenomenon occurs from the Δ G H -negative Pt surface to the Δ G H -positive carrier surface, contributing to the enhancement of kinetic rate and catalytic performance.…”