Catalysts improve fuel cells

Researchers at the US Department of Energy’s Brookhaven National Laboratory have published details about catalysts that could improve the performance of fuel cells.

The researchers looked at two nanomaterial catalysts, gold-cerium oxide and gold-titanium oxide, which can act to reduce the amount of carbon monoxide (CO) produced by a fuel cell using the water-gas shift (WGS) reaction.

This reaction combines the CO, produced by the hydrogen-rich materials feeding the fuel cell, with water to create additional hydrogen and CO₂. This improves the efficiency of fuel cells by providing more fuel, as well as removing the ‘poisonous’ CO which degrades the platinum catalyst used to convert hydrogen into electricity. The catalysts have enabled the WGS to convert nearly 100 per cent of the CO into CO₂.

‘These nanomaterials have recently been reported as very efficient catalysts for the WGS reaction,’ said Brookhaven chemist, Jan Hrbek. ‘This was a surprising finding because neither bulk gold nor bulk ceria and titania are active as catalysts.’