Iron production electrified

Abstract

Scientists have long dreamt of converting molten iron oxide to iron and oxygen using electricity. An anode material that withstands the high temperatures and corrosive chemicals involved brings the dream closer to reality. See Letter p.353 Metals production is the largest industrial source of greenhouse gases, with steel the main culprit. Traditional methods of extracting iron from its ore require a carbon-based reductant and produce large quantities of CO2. Molten oxide electrolysis is a promising alternative, but until now it has required anode materials that are either consumable or prohibitively expensive. This paper reports the development of a new chromium-based aluminium alloy electrode that is relatively cheap and, thanks to its three-layered structure (metal oxide/mixed oxide/electrolyte), is protected from dissolution. This technology must now be scaled up and its long-term performance assessed.