Atomic layer deposition of highly dispersed Pt nanoparticles on a high surface area electrode backbone for electrochemical promotion of catalysis

- A novel EPOC catalyst design based on atomic layer deposition is proposed.
- Highly dispersed Pt nanoparticles deposited on high surface area electrode backbone.
- Pt nanoparticles (average size 6.5 nm) were electropromoted for propane oxidation.
- The catalytic rate was enhanced upon positive polarization up to 33%.
- Electrochemical promotion leads to apparent Faradaic efficiency of 1000-3860%.

A novel catalyst design for electrochemical promotion of catalysis (EPOC) is proposed which overcomes the main bottlenecks that limit EPOC commercialization, i.e., the low dispersion and small surface area of metal catalysts. We have increased the surface area by using a porous composite electrode backbone made of (La0.8Sr0.2)0.95MnO3-δ/Ce0.9Gd0.1O1.95 (LSM/GDC). Highly dispersed Pt nanoparticles with an average diameter of 6.5 nm have been deposited on LSM/GDC by atomic layer deposition (ALD). This novel design offers, for the first time, a controllable and reproducible method for the fabrication of EPOC catalysts. The bare electrode backbone shows negligible activity for propane oxidation, while in the presence of Pt nanoparticles a high catalytic activity is obtained above 200 °C. The performance of the Pt-loaded LSM/GDC catalyst was significantly improved by application of small currents (I < 500 μΑ), leading to a 27-33% increase as a function of the open circuit catalytic rate, with apparent Faradaic efficiency values ranging from 1000 to 3860% at 300 °C. Our results demonstrate that EPOC is a valid approach for enhancing the catalytic activity of nano-structured catalysts.

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