O2 reduction on a Au film electrode in an ionic liquid in the absence and presence of Mg2+ ions: Product formation and adlayer dynamics

Influence of Additives on the Reversible Oxygen Reduction Reaction/Oxygen Evolution Reaction in the Mg2+ -Containing Ionic Liquid N-Butyl-N-Methylpyrrolidinium Bis(Trifluoromethanesulfonyl)imide

The influence of different additives on the oxygen reduction reaction/oxygen evolution reaction (ORR/OER) in magnesium-containing N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide ([BMP][TFSI]) on a glassy carbon electrode was investigated to gain a better understanding of the electrochemical processes in Mg-air batteries. 18-Crown-6 was used as a complexing agent for Mg ions to hinder the passivation caused by their reaction with ORR products such as superoxide and peroxide anions. Furthermore, borane dimethylamine complex (NBH) was used as a potential water-removing agent to inhibit electrode passivation by reacting with trace impurities of water. The electrochemical processes were characterized by differential electrochemical mass spectrometry to monitor the consumed and evolved O2 in the ORR/OER and determine the number of transferred electrons. Crown ether and NBH efficiently masked Mg2+ . A stochiometric excess of crown ether resulted in reduced formation of a passivation layer, whereas at too high concentrations the reversibility of the ORR/OER was diminished.

Special Topic on Interfacial Electrochemistry and Photo(electro)catalysis

Interfacial electrochemistry and photo(electro)catalysis are key processes that convert the energy of photons or electrons to chemical bonds in many energy conversion and storage technologies. Achieving a molecular level understanding of the fundamental interfacial structure, energetics, dynamics, and reaction mechanisms that govern these processes represents a broad frontier for chemical physics and physical chemistry. This Special Topic contains a collection of articles that range from the development of new experimental and computational techniques to the novel application of those techniques for mechanistic studies, as the principal investigators seek a fundamental molecular understanding of both electrode/electrolyte interfaces and the relevant electrocatalytic, photocatalytic, and photoelectrochemical reactions taking place thereabout. Altogether, this collection of articles captures the current state of this very active, frontier research field and highlights the current and remaining key scientific challenges and opportunities.