Using Heteropolyacids in the Anode Catalyst Layer of Dimethyl Ether PEM Fuel Cells

摘要

In this study, polarization experiments were performed on a direct dimethyl ether fuel cell (DMEFC). The experimental setup allowed for independent control of water and DME flow rates. Thus the DME flow rate, backpressure, and water flow rate were optimized. Three heteropoly acids, phosphomolybdic acid (PMA), phosphotungstic acid (PTA), and silicotungstic acid (STA) were incorporated into the anode catalyst layer in combination with Pt/C. Both PTA-Pt and STA-Pt showed higher performance than the Pt control at 30 psig of backpressure. Anodic polarizations were also performed, and Tafel slopes were extracted from the data. The trends in the Tafel slope values are in agreement with the polarization data. The addition of phosphotungstic acid more than doubled the power density of the fuel cell, compared to the Pt control.