Enhancing the Electrocatalytic Activity of Redox Stable Perovskite Fuel Electrodes in Solid Oxide Cells by Atomic Layer-Deposited Pt Nanoparticles

摘要

The carbon dioxide and steam co-electrolysis in solid oxide cells offers an efficient way to store the intermittent renewable electricity in the form of syngas (CO + H-2), which constitutes a key intermediate for the chemical industry. The co-electrolysis process, however, is challenging in terms of materials selection. The cell composites, and particularly the fuel electrode, are required to exhibit adequate stability in redox environments and coking that rules out the conventional Ni cermets. La0.75Sr0.25Cr0.5Mn0.5O3 (LSCrM) perovskite oxides represent a promising alternative solution, but with electrocatalytic activity inferior to the conventional Ni-based cermets. Here, we report on how the electrochemical properties of a state-of-the-art LSCrM electrode can be significantly enhanced by introducing uniformly distributed Pt nanoparticles (18 nm) on its surface via the atomic layer deposition (ALD). At 850 degrees C, Pt nanoparticle deposition resulted in a similar to 62% increase of the syngas production rate during electrolysis mode (at 1.5 V), whereas the power output was improved by similar to 84% at fuel cell mode. Our results exemplify how the powerful ALD approach can be employed to uniformly disperse small amounts (similar to 50 mu g.cm(-2)) of highly active metals to boost the limited electrocatalytic properties of redox stable perovskite fuel electrodes with efficient material utilization.