Challenges in developing sulfur-tolerant and carbon-resistant catalysts for reforming of logistic fuels for fuel cells

This overview discusses the challenges and opportunituies in processing and reforming of logistic fuels for fuel cell applications. Logistic fuels are high-density liquid fuels which may contain up to 3000 ppmw sulfur in jet fuels and 10,000 ppmw in military diesel fuels. These fuels are greatly different from the commercially available highway automotive fuels that will only contain less than 30 ppm sulfur starting in September 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 need to involve effectives measures of deep sulfur removal without using high-pressure high-temperature reactor, and sulfur-tolerant and carbon-resistant catalysts for reforming. For mobile fuel processor, 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. Recent development in our laboratory will be discussed on the sulur-tolerant and carbon-resistant catalysts for low-temperature steam reforming. More background information is available in recent reviews [C.S. Song, Fuel Processing for Low-Temperature and High-Temperature Fuel Cells. Challenges, and Opportunities for Sustainable Development in the 21st Century. Catalysis Today, 2002, 77, 17-50; C.S. Song, An Overview of New Approaches to Deep Desulfurization for Ultra-Clean Gasoline, Diesel Fuel and Jet Fuel. Catalysis Today, 2003, 86, 211-263].