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Energy & Fuels 2005, 19, 2214-2215
Communications Low-Temperature Removal of H2S by Nanoporous Composite of Polymer-Mesoporous Molecular Sieve MCM-41 as Adsorbent for Fuel Cell Applications Xiaochun Xu, Ivan Novochinskii, and Chunshan Song* Clean Fuels and Catalysis Program, The Energy Institute, and Department of Energy and Geo-Environmental Engineering, Pennsylvania State University, 209 Academic Projects Building, University Park, Pennsylvania 16802 Received March 12, 2005. Revised Manuscript Received July 7, 2005 Fuel cells are promising candidates as more-energyefficient conversion devices for generating electricity for residential and mobile applications, as well as stationary power plants.1 However, several challenges in regard to practical applications still need to be overcome. One such challenge is the presence of sulfur compounds, which are poison for fuel processing catalysts and fuel cell anodes.1 Therefore, sulfur compounds in hydrocarbon fuels must be removed before the fuels enter the fuel cell devices. Selective adsorption for removing sulfur (SARS) provides an option for on-site or on-board removal of organic sulfur species from liquid hydrocarbon fuels for fuel cell systems.2 In addition, reformate from the autothermal reforming of hydrocarbon fuels may contain H2S at parts per million (ppm) levels, which can deactivate the catalysts for subsequent processing (such as water-gas-shift) and also poison the anode catalysts that are based on platinum.1 On the other hand, the large-scale natural gas sweetening processes, such as the Girdler process (liquid amine absorption), and solid desiccants (wet iron sponge) cannot reduce the natural gas sulfur content to the low levels that are required. In addition, natural gas distributors are required by law to add nontoxic odorantss generally sulfur-based odorantssto permit factory detection of leaks. To be useful for fuel cells, the natural gas processing must remove the residual sulfur that is not removed by the initial sweetening process, as well as the odorants that were added for public safety. Therefore, onsite or on-board H2S removal may be necessary. Some recent studies examined solid adsorbents such as ZnO to capture H2S from reformate before it enters the watergas-shift reactor.3 However, even solid oxide fuel cells (SOFCs) require the reduction of sulfur in natural gas from several parts per million by volume (ppmv) to
