New electrochemical ammonia (NH3) synthesis technologies are of interest as a complementary route for the Haber-Bosch (HB) method for distributed fertilizer generation, and towards exploiting ammonia as a zero-carbon fuel produced by means of renewably-sourced electricity. Apropos of these ambitions can be a surge of basic analysis targeting heterogeneous supplies as electrocatalysts for the nitrogen reduction reaction (N2RR). These systems usually suffer from poor stability and NH3 selectivity; competitive hydrogen evolution reaction (HER) outcompetes N2RR. Molecular catalyst systems is usually exquisitely tuned and provide an option method, but progress has thus far been thwarted by the exact same selectivity challenge; HER dominates. Herein we describe a tandem catalysis approach that offers a resolution to this puzzle. A molecular complex that will mediate an N2 reduction cycle is partnered with a co-catalyst that interfaces the electrode and an acid to mediate concerted proton-electron transfer (CPET) actions, facilitating N鈭扝 bond formation at a favorable applied possible and all round thermodynamic efficiency. Without the need of CPET, particular intermediates in the N2RR cycle would be unreactive through independent electron transfer (ET) or proton transfer (PT) methods, thereby shunting the technique. Promisingly, complexes featuring a number of metals (W, Mo, Os, Fe) achieve N2RR electrocatalysis in the very same applied potential in the presence of the CPET mediator, pointing for the generality of this tandem approach. Formula of 8-Bromoimidazo[1,5-a]pyridine 170097-87-7 Purity PMID:25016614