Mass Spectrometry of SOFC Fuel Mixtures Containing Phosphine

作者：Finklea Harry O^*; Zhang Wei; Jony Mahfuzur; Demirgok Berk

来源：Journal of the Electrochemical Society, 2015, 162(9): F1101-F1105.

DOI：10.1149/2.1051509jes

Phosphine (PH3) is present at ppm concentrations in coal syngas, a potential fuel source for solid oxide fuel cells (SOFCs). A mass spectrometer is used to monitor fuel mixtures of hydrogen and phosphine after exposure to two environments. In the first environment, the gas mixtures are passed through a heated zone in a tube furnace. In the second environment, the gas mixtures are passed across the anodes of operating SOFCs, both electrolyte- and anode-supported. Phosphine appears to react with residual oxygen in dry hydrogen at intermediate temperatures (400-600 degrees C) but is stable above 600 degrees C. Phosphine reacts with water in wet hydrogen mixtures and with a Ni/YSZ anode at temperatures above 400 degrees C. Evidence is presented for deposition of non-volatile contaminants following prolonged phosphine exposure. The contaminants react with dry hydrogen to generate PH3 at 800 degrees C. Mass spectra of the anode exhaust of an electrolyte-supported SOFC show that a few torr of water, either present initially or electrochemically generated by fuel oxidation, is sufficient to suppress the phosphine signal. At all gas compositions and currents, no new mass signals were detected in the mass range of 45-100, suggesting that HPO, HPO2 and HPO3 are not products of phosphine reaction or electrochemical oxidation.

• 出版日期2015