title: Nitrogen electrochemically reduced to ammonia with hematite: density-functional insights.
abstract: Licht et al. (Science, 2014, 345, 637) recently proposed a procedure to synthesize NH3 from N2 and by steam electrolysis in molten hydroxide suspensions of nano-Fe2O3. This highly exciting investigation undoubtedly boosts the hope of the CO2-free and low-cost ammonia industry. To provide insights at the atomistic level into the reduction process of N2, we have carried out a density-functional study on the electrochemical formation of NH3 molecules on hematite(0001) surfaces. By considering associative and dissociative mechanisms, we have identified a reaction path that requires an applied bias of -1.1 V to allow the proton transfer processes to occur downhill. The most energy-demanding step is the addition of the first proton to the adsorbed molecular nitrogen. The computed bias is in good agreement with experimental electrolysis potentials that activate the electric current.
authors.affiliation: The Abdus Salam International Centre for Theoretical Physics, Strada Costiera 11, 34151 Trieste, Italy. manhth.nguyen@gmail.com.
authors.forename: Manh-Thuong
authors.initials: MT
authors.lastname: Nguyen
authors.forename: Nicola
authors.initials: N
authors.lastname: Seriani
authors.forename: Ralph
authors.initials: R
authors.lastname: Gebauer