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In this present work, the effect of anode electrocatalyst materials is investigated by adding NiTiO 3 with Pt/C and Pt-Ru/C for the performance enhancement of direct methanol fuel cells (DMFCs). The supportive material NiTiO 3 /C has been synthesized first by wet chemical method followed by incorporation of Pt and Pt-Ru separately. Experiments are conducted with the combination of four different electrocatalyst materials on the anode side (Pt/C, Pt-NiTiO 3 /C, PtRu/C, Pt-Ru-NiTiO 3 /C) and with commercial 20 wt. % Pt/C on the cathode side; 0.5 mg pt /cm 2 loading is maintained on both sides. The performance tests of the above catalysts are conducted on 5 cm 2 active area with various operating conditions like cell operating temperatures, methanol/water molar concentrations and reactant flow rates. Best performing operating conditions have been optimized. The maximum peak power densities attained are 13.30 mW/cm 2 (26.6 mW/mg pt) and 14.60 mW/cm 2 (29.2 mW/mg pt) for Pt-NiTiO 3 /C and Pt-Ru-NiTiO 3 /C at 80 , respectively, with 0.5 M concentration of methanol and fuel flow rate of 3 ml/min (anode) and oxygen flow rate of 100 ml/min (cathode). Besides, 5 h short term stability tests have been conducted for PtRu/C and Pt-NiTiO 3 /C. The overall results suggest that the incorporation of NiTiO 3 /C supportive material to Pt and Pt-Ru appears to make a promising anode electrocatalysts for the enhanced DMFC performances.

Voltage degradation is the main parameter that determines the effective usable life of a fuel cell, here the influence of Pt/C% and relative humidity (RH%) on the voltage decay rate of a fuel cell is experimentally evaluated and reported.This study implements a stress test with frequent interrupts of purging for determining the durability of the fuel cells. In the course of the 1456 h stress test for each membrane electrode assembly (MEA), the polarization curve and electrochemical impedance spectroscopy (EIS) were measured. The experimental results make it evident that the lowest voltage degradation was 6 µV/h for MEA with 40% Pt/C tested under 70% RH while the highest was 183 µV/h recorded for MEA with 20% Pt/C tested under 90% RH. From EIS results, the ohmic resistance increased for all the tested MEAs, which is also reflected in the performance degradation. Field emission scanning electron microscopy images also indicate the delamination of MEA layers which in turn increases the electron transfer resistance. So, the decisive factors for the fuel cell performance degradation were flooding, catalyst surface contamination, and delamination of MEA layers due to repeated mechanical and chemical stresses.