Ultralow-Loading Ruthenium Catalysts by Plasma-Enhanced Atomic Layer Deposition for a Solid Oxide Fuel Cell
Seunghyeon Kye, Hyong June Kim, Dohyun Go, Byung Chan Yang, Jeong Woo Shin, Sungje Lee, Jihwan An
Abstract
Designing and fabricating highly active and thermally stable catalysts with minimal noble-metal loading is crucial for solid oxide fuel cells that operate with direct methane fuel. In this study, ultralow-loading Ru catalysts (<10 μg cm–2) are fabricated using plasma-enhanced atomic layer deposition (PEALD) on a samaria-doped ceria (SDC) backbone for a methane oxidation electrode. The Ru catalyst with a high surface area and a high triple-phase boundary density shows electrochemical performance superior to that of its sputtered counterpart despite a 95% reduction in noble-metal loading. Furthermore, the PEALD Ru catalyst demonstrates more stable operation at elevated temperatures with less morphological degradation in comparison to the sputtered catalyst and mitigates carbon coking. Such improvements are ascribed to the nature of PEALD, which can make Ru particles conformally on porous SDC with highly dense and intimate interfaces.