Graduate Student Muhammad Bilal

"High-performance Pt alloy electrocatalysts for fuel cells"

Future energy demands, diminishing fossil fuels, and escalating climate problems present severe challenges to sustainable human society. Development of efficient energy storage and conversion technologies is critical towards achieving the future energy targets and mitigating climate change. Fuel cells are a promising energy conversion technolo-gy for electrifying the transportation sector and can even replace batteries in portable electronic devices. In a fuel cell, Platinum (Pt) is used as an electrocatalyst for the anodic oxidation and cathodic reduction reaction because of its opti-mum binding energy with reaction intermediates 1–3. However, high cost, limited catalytic activity and stability of Pt hin-ders the widespread applications of fuel cells. By alloying Pt with transition metals such as Ni and Co, a great room for improvement is available for achieving the desired performance at a reduced cost. I will present different strategies to modify the composition and morphology of Pt-based alloy electrocatalysts for high performance fuel cells 4–6. The modi-fication of electronic structure and engineering the near surface composition of Pt alloy nanostructures greatly increase the activity, selectivity, and stability of the electrocatalyst. Exposure of reactants to high index facets and modification of the binding energy through strain and ligand effects is achieved through controlled synthetic procedures. A several times increase in specific activity (mA.cm-2) and mass activity (mA.g-1) at reduced overpotential can pave the way towards large-scale implementation of fuel cell technology.

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3. Ly, A., Asset, T. & Atanassov, P. Integrating nanostructured Pt-based electrocatalysts in proton exchange membrane fuel cells. J. Power Sources 478, 228516 (2020).
4. Tian, X. et al. Engineering bunched Pt-Ni alloy nanocages for efficient oxygen reduction in practical fuel cells. Science (80-. ). 366, 850–856 (2019).
5. Chen, S. et al. High-Performance Pt − Co Nanoframes for Fuel-Cell Electrocatalysis.Nano Lett. 20, 1974-1979 (2020).
6. Zhu, X., Huang, L., Wei, M., Tsiakaras, P. & Kang, P. Highly stable Pt-Co nanodendrite in nanoframe with Pt skin structured catalyst for oxygen reduction electrocatalysis. Applied Catalysis B : Environmental, 281, 1–9 (2021).