Near thermal, selective liberation of hydrogen from formic acid catalysed by copper hydride ate complexes

Abstract

Copper hydride ate complexes can effectively catalyse the selective decomposition of formic acid into carbon dioxide and hydrogen.

CO2/13CO2 Dynamic Exchange in the Formate Complex [(2,9-(tBu)2-phen)Cu(O2CH)] and Its Catalytic Activity in the Dehydrogenation of Formic Acid

“…At last, in 2023, O’Hair and co-workers revealed that the mononuclear cuprate hydride anions [(X)­CuH] − (X = H – , O 2 CH – , BH 4 – , and CN – ) reacted in the gas phase with formic acid to release H 2 with the formation of the formate [(X)­Cu­(O 2 CH)] − compound. The latter decarboxylates readily via collision-induced dissociation to regenerate the initial copper hydride …”

“…The latter decarboxylates readily via collision-induced dissociation to regenerate the initial copper hydride. 78 The dynamic exchange process of 1 under CO 2 suggested that it could be a rare copper catalyst for the dehydrogenation of formic acid. We reasoned that if the hydride intermediate could trap gaseous CO 2 , it should also react quickly with the acid HCO 2 H, which is liquid and more abundant in solution than a gas (Scheme 3).…”

Liberation of carbon monoxide from formic acid mediated by molybdenum oxyanions

“…8 A range of charged metal hydride complexes have been reported to mediate the selective gas-phase decomposition of HCO 2 H into CO 2 and H 2 , and all follow a similar two-step formal catalytic cycle (cycle 1, Scheme 1B) with similar mechanistic features. 5,6,9 In step one, the coordinated hydride undergoes an ion-molecule reaction with formic acid to liberate hydrogen in which the coordinated hydride is replaced by a coordinated formate. Step two involves decarboxylation of the coordinated formate – here the coordinated formate acts as a hydride donor (Scheme 1C).…”