Challenges in developing sulfur-tolerant catalysts for low-temperature reforming of liquid hydrocarbon fuels for fuel cells

This presentation discusses the challenges and opportunities in developing catalysts and sorbents for liquid fuel processing for fuel cells. Liquid logistic fuels in the middle distillate range are high-density hydrocarbon fuels which may contain up to 3000 ppmw sulfur in jet fuels and 10,000 ppmw in diesel fuels. These fuels are greatly different from the commercially available highway automotive fuels that contain less than 30 ppmw sulfur starting in Sept. 2006. The logistic fuels also have higher contents of polyaromatic compounds and some oxygen-containing polar species as well as nitrogen compounds. Fuel processing of such logistic fuels requires effective method for deep sulfur removal without using high-pressure high-temperature reactor, and sulfur-tolerant and carbon-resistant catalysts for reforming. Recent development in our laboratory will be discussed on the sulfur-tolerant and carbon-resistant bimetallic catalysts for low-temperature steam reforming [J.J. Strohm at al., J. Catal., 2006, 238 (2) 309-320] along with the selective adsorption for removing sulfur [C.S. Song, Catal. Today, 2003 (86) 211-263] from liquid hydrocarbon fuels. More background information on FCFP is available in a recent review [C.S. Song, Catal. Today, 2002 (77)17-50]. It should be noted that for stationary or mobile fuel processor using liquid fuels, there are major challenges in the development of (1) fuel processor for on-site or on-board production of H2 that meets the stringent requirement of H2S (<20 ppbv) and CO (<10 ppmv) for H2-based proton-exchange membrane fuel cell system, and (2) fuel processor for synthesis gas production for solid-oxide fuel cells that use hydrocarbon fuels.