Atomic layer deposition of ruthenium surface-coating on porous platinum catalysts for high-performance direct ethanol solid oxide fuel cells

• Published in: Journal of power sources Vol. 291; pp. 239 - 245
• Main Authors: Jeong, Heon Jae, Kim, Jun Woo, Jang, Dong Young, Shim, Joon Hyung
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 30.09.2015
• Subjects: Atomic layer deposition; Direct ethanol solid oxide fuel cells; Heterogeneous catalysts; Platinum; Ruthenium; Ruthenium; Atomic layer deposition; Heterogeneous catalysts; Platinum; Direct ethanol solid oxide fuel cells
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2015.05.005

Pt–Ru bi-metallic catalysts are synthesized by atomic layer deposition (ALD) of Ru surface-coating on sputtered Pt mesh. The catalysts are evaluated in direct ethanol solid oxide fuel cells (DESOFCs) in the temperature range of 300–500 °C. Island-growth of the ALD Ru coating is confirmed by transmission electron microscopy and X-ray photoelectron spectroscopy (XPS) analyses. The performance of the DESOFCs is evaluated based on the current–voltage output and electrochemical impedance spectroscopy. Genuine reduction of the polarization impedance, and enhanced power output with improved surface kinetics are achieved with the optimized ALD Ru surface-coating compared to bare Pt. The chemical composition of the Pt/ALD Ru electrode surface after fuel cell operation is analyzed via XPS. Enhanced cell performance is clearly achieved, attributed to the effective Pt/ALD Ru bi-metallic catalysis, including oxidation of CO by Ru, and de-protonation of ethanol and cleavage of C–C bonds by Pt, as supported by surface morphology analysis which confirms formation of a large amount of carbon on bare Pt after the ethanol-fuel-cell test. •Bi-metallic electrodes were synthesized by ALD Ru coating on sputtered Pt mesh.•Island-growth of ALD Ru was observed on the Pt surface.•High ethanol-fuel-cell performance was achieved with Pt/ALD Ru 50 below 500 °C.•Carbon content was significantly reduced due to bi-functional catalysis by Pt/Ru.