Taking carbon out of the ammonial recipe: The reaction used to make ammonia for synthetic fertilizer requires hydrogen. Nowadays, that hydrogen is stripped from methane, creating CO ₂ as a by-product. Licht et al. demonstrate a relatively efficient electrochemical process in which water and nitrogen react directly to form ammonia. The approach removes the need for an independent hydrogen generation step. The process takes place in molten hydroxide salt and requires a nanostructured iron oxide–derived catalyst. Although the catalyst suspension is currently only stable for a few hours, the protocol points to a way to produce ammonia from purely renewable resources. Science , this issue p. 637

Higher capacity batteries based on an unusual stabilized iron(VI) chemistry are presented. The storage capacities of alkaline and metal hydride batteries are largely cathode limited, and both use a potassium hydroxide electrolyte. The new batteries are compatible with the alkaline and metal hydride battery anodes but have higher cathode capacity and are based on available, benign materials. Iron(VI/III) cathodes can use low-solubility K ₂ FeO ₄ and BaFeO ₄ salts with respective capacities of 406 and 313 milliampere-hours per gram. Super-iron batteries have a 50 percent energy advantage compared to conventional alkaline batteries. A cell with an iron(VI) cathode and a metal hydride anode is significantly (75 percent) rechargeable.

New molten salt chemistry allows solar thermal energy to drive calcium oxide production without any carbon dioxide emission. This is accomplished in a one pot synthesis, and at lower projected cost than the existing cement industry process, which after power production, is the largest contributor to anthropogenic greenhouse gas emissions.

We report a fundamental change in the understanding of iron oxide thermochemistry, opening a facile, new CO₂-free route to iron production. The resultant process can eliminate a major global source of greenhouse gas emission, producing the staple iron in molten media at high rate and low electrolysis energy.