Core-shell and heterostructured silver-nickel nanocatalysts fabricated by gamma-radiation induced synthesis for oxygen reduction in alkaline media
Journal article, 2022

To reach commercial viability for fuel cells, one needs to develop active and robust Pt-free electrocatalysts. Silver has great potential to replace Pt as the catalyst for the oxygen reduction reaction (ORR) in alkaline media due to its low cost and superior stability. However, its catalytic activity needs to be improved. One possible solution is to fabricate bimetallic nanostructures, which demonstrate a bifunctional enhancement in the electrochemical performance. Here, two types of bimetallic silver-nickel nanocatalysts, core-shells (Ag@NiO) and heterostructures (Ag/Ni), are fabricated using gamma-radiation induced synthesis. The Ag@NiO nanoparticles consist of an amorphous, NiO layer as a shell and a facetted crystalline Ag particle as a core. Meanwhile, the Ag/Ni heterostructures comprise Ag particles decorated with Ni/Ni(oxy-hydro)-oxide clusters. Both materials demonstrate similar and increased alkaline ORR activity as compared to monometallic catalysts. It was revealed that the enhanced catalytic activity of the core-shells is mainly attributed to the electronic ligand effect. While in the Ag/Ni heterostructures, a lattice mismatch between the Ni-based clusters and Ag implies a significant lattice strain, which, in turn, is responsible for the increased activity of the catalyst. Also, the Ag/Ni samples exhibit good stability under operating conditions due to the existence of stable Ni3+ compounds on the surface.

Author

Yi Yang

Royal Institute of Technology (KTH)

Gerard Montserrat Siso

Chalmers, Physics, Chemical Physics

Björn Wickman

Chalmers, Physics, Chemical Physics

Pavel Anatolyevich Nikolaychuk

Tyumen State University

Inna L. Soroka

Royal Institute of Technology (KTH)

Dalton Transactions

1477-9226 (ISSN) 1477-9234 (eISSN)

Vol. 51 9 3604-3615

Material för effektiva och konkurrenskraftiga bränsleceller

Swedish Foundation for Strategic Research (SSF) (EM16-0060), 2018-01-16 -- 2022-12-31.

New fuel cell catalyst materials with nanostructured model electrodes

Swedish Research Council (VR) (2018-03927), 2019-01-01 -- 2022-12-31.

Subject Categories

Inorganic Chemistry

Other Chemical Engineering

Other Chemistry Topics

DOI

10.1039/d1dt03897d

PubMed

35147619

More information

Latest update

3/3/2022 1