Cambridge, Massachusetts [MIT Technology Insider] High-temperature fuel cells promise clean, efficient energy in quantities large enough to power cities. But, so far, they’ve been too expensive for widespread use. One major problem is the sulfur in fossil fuels, such as coal, oil, and natural gas, which contaminates the hydrogen gas that runs the cells. The sulfur attacks and degrades a part of the fuel cell called the anode, reducing power production — and eventually shutting down the cell. Now chemical engineers at Tufts University in Medford, MA, led by Maria Flytzani-Stephanopoulos, have found a way to continuously remove sulfur from incoming hydrogen before it feeds these cells. The work could be a significant step in making high-temperature fuel cells practical.