A Non‐Exploding Alkali Metal Drop on Water: From Blue Solvated Electrons to Bursting Molten Hydroxide

Abstract

Alkali metals in water are always at the brink of explosion. Herein, we showt hat this vigorous reaction can be kept in an on-exploding regime,r evealing af ascinating richness of hitherto unexplored chemical processes.Acombination of high-speed camera imaging and visible/near-infrared/infrared spectroscopya llowed us to catcha nd characterize the system at each stage of the reaction. After gently placing adrop of as odium/potassium alloy on water under an inert atmosphere,t he production of solvated electrons became so strong that their characteristic blue color could be observed with the naked eye.T he exoergic reaction leading to the formation of hydrogen and hydroxidee ventually heated the alkali metal drop such that it became glowingr ed, and part of the metal evaporated. As aresult of the reaction, aperfectly transparent drop consisting of molten hydroxidewas temporarily stabilized on water through the Leidenfrost effect, bursting spectacularly after it had cooled sufficiently.

Potassium and Water Coadsorption on TiO2(110): OH-Induced Anchoring of Potassium and the Generation of Single-Site Catalysts

“…The evaporation of small gold clusters onto this surface indicates that the potassium can provide sites for nucleation of the gold, which may prove to be relevant when considering alkali metal promotion effects for Au/TiO 2 catalysts. The strong interaction of the alkali with the oxide modifies the intrinsic vigorous reaction of K with water, 40 but the system still remains very reactive towards O-H bond cleavage.…”