Study of Formaldehyde and Formic Acid Contamination Effect on PEMFC

The contamination effect of formaldehyde (HCHO) and formic acid (HCOOH) was studied using state-of-the-art automotive PEMFC stacks and with high fuel utilization and automotive-type operation with hydrogen recirculation. The results, measured at current density of 0.6 A/cm², show that the contamination effect of formaldehyde was observable when the concentration was 2 ppm, 200 times higher than the current limit in the ISO 14687-2:2012 standard. The effect of formaldehyde was less than 10% compared to 2 ppm of CO in the same operating conditions. Moreover, the contamination effect of formic acid was barely measurable at 2 ppm, corresponding to a concentration 100 times the limit of the ISO standard. Thus, the limits of HCHO and HCOOH in the current ISO standard seem to be too strict.