Coke-Free Oxidation of Methanol in Solid Oxide Fuel Cells with Heterogeneous Nickel-Palladium Catalysts Prepared by Atomic Layer Deposition

Abstract

Bimetallic Ni/Pd anodic catalysts are synthesized for application in direct methanol solid oxide fuel cells (DMSOFCs). Pd nanoparticles are deposited on the surface of porous Ni, prepared by sputtering, via atomic layer deposition (ALD). The amount of ALD Pd is optimized by varying the number of ALD cycles (150, 300, and 600 cycles). The power output of fuel cells employing the ceramic electrolyte-support pellets is enhanced by 3-6 times with optimal ALD Pd treatment compared to that of the cell with a bare Ni anode. The anode kinetics and stability against carbon coking are significantly improved by the ALD Pd surface treatment. The surface of the anode with ALD Pd remains clean after a fuel cell test with methanol, whilst severe growth of carbon fibers is observed on the bare Ni surface. The ALD Pd cell exhibits superior long-term stability compared to the bare Ni anode.