Alloying–realloying enabled high durability for Pt–Pd-3d-transition metal nanoparticle fuel cell catalysts

Abstract

Alloying noble metals with non-noble metals enables high activity while reducing the cost of electrocatalysts in fuel cells. However, under fuel cell operating conditions, state-of-the-art oxygen reduction reaction alloy catalysts either feature high atomic percentages of noble metals (>70%) with limited durability or show poor durability when lower percentages of noble metals (<50%) are used. Here, we demonstrate a highly-durable alloy catalyst derived by alloying PtPd (<50%) with 3d-transition metals (Cu, Ni or Co) in ternary compositions. The origin of the high durability is probed by in-situ/operando high-energy synchrotron X-ray diffraction coupled with pair distribution function analysis of atomic phase structures and strains, revealing an important role of realloying in the compressively-strained single-phase alloy state despite the occurrence of dealloying. The implication of the finding, a striking departure from previous perceptions of phase-segregated noble metal skin or complete dealloying of non-noble metals, is the fulfilling of the promise of alloy catalysts for mass commercialization of fuel cells.

Engineering Platinum–Cobalt Nano‐alloys in Porous Nitrogen‐Doped Carbon Nanotubes for Highly Efficient Electrocatalytic Hydrogen Evolution

“…Recently, a PtPdCu ternary oxygen reduction reaction electrocatalyst has been proved to be active and stable in the acidic media due to realloying. [44] This agrees well with our experimental observations showing limited amount of Co leaching after the durability test in acidic electrolyte and demonstrates great promise of nano-alloy electrocatalysts in acidic media.…”

Subnanometer high-entropy alloy nanowires enable remarkable hydrogen oxidation catalysis

“…As promising catalysts in heterogeneous catalysis, HEAs generally consist of five or more metals, which display the structure-dependent synergistic effects and enhanced catalytic performance in terms of activity and durability 13 , 14 . Moreover, since the HEAs can largely decrease the usage of noble metals and thus reduce the cost of catalyst 15 , they have been attracted increasing research interests. For instance, Li et al 16 reported a small HEAs Pt 18 Ni 26 Fe 15 Co 14 Cu 27 nanoparticles (NPs) with a mean size of ~3.4 nm as an efficient catalyst for alkaline methanol oxidation reaction, on which the synergistic effects facilitate the site-to-site electron transfer during both reduction and oxidation processes.…”

Hydrogen production from water electrolysis: role of catalysts

“…It is the role of catalysis in electrolysis water-splitting cells that is the focal point of this review. The readers are referred to several recent reviews for the role of catalysis in fuel cells [15,[19][20][21][22][23][24][25][26].…”