Improved the Methanol Electro-Oxidation and Carbon Monoxide Tolerance for Direct Methanol Fuel Cells Using Strontium Molybdate

A high methanol electro-oxidation (MOR) and carbon monoxide (CO) tolerance satisfied the electrochemical requirements of direct methanol fuel cells (DMFCs). The study investigated strontium molybdate (SrMoO4) mixed with Vulcan XC-72, carbon-loaded with 20% Pt. The electrochemical performance was confirmed by MOR and CO tolerance activities measured via cyclic voltammetry (CV). The synergistic effect between Pt and SrMoO4 is essential to affect the electrochemical characteristic. SrMoO4 can help remove CO-like intermediate products on the Pt surface, enhancing electrochemical performance for DMFCs. In addition, HxMoO3/HyMoO3 existence in Sr0.5Mo0.5O4−δ can quickly remove intermediates from Pt surfaces and accelerate the transformation of adsorbed intermediates to CO2. The results obtained showed that 20%-Pt/uncalcined Sr0.5Mo0.5O4−δ-C electrocatalyst has higher MOR and CO tolerance ability in DMFCs. Furthermore, the fabricated DMFC shows excellent long-term electrochemical stability after 1000 cycles and a maximum power density (1.42 mW/cm2) higher than commercial 20%-Pt/C (1.27 mW/cm2).

Pt-Amorphous Barium Aluminum Oxide/Carbon Catalysts for an Enhanced Methanol Electrooxidation Reaction

A new type of amorphous barium aluminum oxide was synthesized using a polyol thermal method involving a mixture with Vulcan XC-72 carbon and supported with 20%Pt catalysts to enhance the activity of a methanol electrooxidation reaction (MOR). The maximum current density, electrochemically active surface area (ECSA), and electrochemical impedance spectra (EIS) of the obtained catalysts for MOR were determined. The MORs of barium aluminum oxide with different calcination temperatures and Ba and Al contact ratios were studied. The MOR of the uncalcined amorphous Ba0.5AlOx catalysts prepared with a mole ratio of 2/1 Ba/Al mixed with Vulcan XC-72 carbon and supported with 20%Pt catalyst (Pt-Ba0.5AlOx/C) was enhanced compared with that of 20%Pt-Al2O3/C and 20%Pt/C catalysts due to its obtained largest maximum current density of 3.89 mA/cm2 and the largest ECSA of 49.83 m2/g. Therefore, Pt-Ba0.5AlOx/C could provide a new pathway to achieve a sufficient electrical conductivity, and possible synergistic effects with other active components improved the catalytic activity and stability of the prepared catalyst in MOR.