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

Abstract

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).

Enhanced Catalytic Performance and Tolerance to Carbon Monoxide Poisoning of CoO/PtPd/r‐GO Nanocomposite Thin Film for Methanol Fuel Cells

“…There are some reports on applying MO with Pt electrocatalyst to increase the MOR and improve the CO tolerance 55,56 …”

“…There are some reports on applying MO with Pt electrocatalyst to increase the MOR and improve the CO tolerance. 55,56 Generally, there are some reports on the effect of the addition of a third metal that can increase the catalytic activity and reaction progress which is related to electronic charge transfer between three elements that in turn is related to their different ionization potential and electronegativity amounts. Pd (8.30 eV, 2.20) is electropositive metal than Pt (9.00 eV, 2.28) and denotes electron density to neighboring Pt atoms and increases the electron density on the platinum center (Scheme 1) which has already been proven by DFT studies.…”