A new class of catalysts created at Argonne National Laboratory may help engineers overcome some of the hurdles that have inhibited the production of hydrogen for use in fuel cells.
Argonne chemist Michael Krumpelt and his colleagues in
Most hydrogen produced industrially is created through steam reforming. In this process, a nickel-based catalyst is used to react natural gas with steam to produce pure hydrogen and carbon dioxide.
Krumpelt’s initial experiments with single-site catalysts used platinum in gadolinium-doped ceria that, though it started to reform hydrocarbons at temperatures as low as 450oC, became unstable at higher temperatures. As he searched for more robust materials that would support the oxidation-reduction reaction cycle at the heart of hydrocarbon reforming, Krumpelt found that if he used ruthenium in a perovskite matrix, then he could initiate reforming at 450oC and still have good thermal stability.
The use of the LaCrRuO3 perovskite is said to offer an additional advantage over traditional catalysts. While sulphur species in the fuel degraded the traditional nickel, and to a lesser extent even the single-site platinum catalysts, the crystalline structure of the perovskite lattice acts as a stable shell that protects the ruthenium catalyst from deactivation by sulphur.