No abstract

Sublimation of silver atoms from a nanometer-sized silver particle, namely, the crystalline-to-gas transition, has been directly observed by high resolution electron microscopy. Remarkable sublimation of silver atoms took place at 950 K from an approximately 9-nm-sized crystalline silver particle on the graphite substrate. The sublimation continued until the whole silver particle disappeared. No melting of the particle occurred during this process. The height-to-width ratio of a nanometer-sized silver particle on graphite at 950 K was about 0.65, and the ratio did not change so much during the sublimation-induced shrinkage of the particle.

No abstract

Ammonia, a key feedstock used in various industries, has been considered a sustainable fuel and energy storage option. However, NH3 production via the conventional Haber–Bosch process is costly, energy‐intensive, and significantly contributing to a massive carbon footprint. An electrochemical synthetic pathway for nitrogen fixation has recently gained considerable attention as NH3 can be produced through a green process without generating harmful pollutants. This review discusses the recent progress and challenges associated with the two relevant electrochemical pathways: direct and indirect nitrogen reduction reactions. The detailed mechanisms of these reactions and highlight the recent efforts to improve the catalytic performances are discussed. Finally, various promising research strategies and remaining tasks are presented to highlight future opportunities in the electrochemical nitrogen reduction reaction.

No abstract