Highly sulfur-tolerant Pt/Ce0.8Gd0.2O1.9 catalyst for steam reforming of liquid hydrocarbons in fuel cell applications

A sulfur-tolerant Pt catalyst has been developed for fuel processors being developed for use with fuel cells, using a fluorite-type Ce0.8Gd0.2O1.9 support. The catalyst calcination temperature is crucial to ensure the maintenance of sulfur tolerance. The catalyst calcined at 800 °C retained its activity and selectivity for entire 100-h test period in the steam reforming of iso-octane with ⩾300 μg/g of sulfur, whereas the catalyst calcined at 600 °C obviously lost activity in this course. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) for CO and CO/H2S adsorption was performed to characterize the nature of the Pt sites and to evaluate their ability to tolerate sulfur. Strongly electron-deficient Pt sites, evidenced by a CO adsorption band at νmaxνmax 2104–2108 cm−1, were immune to sulfur poisoning and were uniformly formed with the calcination at 800 °C. In addition, thiophene sulfur was completely converted into H2S and likely complied with a redox mechanism.