Additive-free formic acid dehydrogenation catalyzed by a cobalt complex

Lentz Nicolas (1) , Alicia Aloisi (1) , Pierre Thuéry (1) , Emmanuel Nicolas (1) , Thibault Cantat (1)

1 LCMCE - Laboratoire de Chimie Moléculaire et de Catalyse pour l'Energie (ex LCCEF)

The reversible storage of hydrogen through the intermediate formation of formic acid (FA) is a promising solution to its safe transport and distribution. However, the common necessity of using bases or additives in the catalytic dehydrogenation of FA is a limitation. In this context, two new cobalt complexes (1 and 2) were synthesized with a pincer PP(NH)P ligand containing a phosphoramine moiety. Their reaction with an excess FA yields a cobalt(I) hydride complex (3). We report here the unprecedented catalytic activity of 3 in the dehydrogenation of FA, with a turnover frequency (TOF) of 67 min$^{–1}$ measured in the first minute and a turnover number (TON) of 454, without the need for bases or additives. A mechanistic study reveals the existence of ligand–metal cooperativity with intermolecular hydrogen bonding, also influenced by the concentration of formic acid.

Mots clés: catalysis; formic acid; cobalt; catalysis

Domaines: Catalyse

Lentz Nicolas, Alicia Aloisi, Pierre Thuéry, Emmanuel Nicolas, Thibault Cantat. Additive-free formic acid dehydrogenation catalyzed by a cobalt complex. Organometallics, 2021, 40 (5), pp.565-569. ⟨10.1021/acs.organomet.0c00777⟩. ⟨cea-02933763v2⟩