Hydrogen production from formic acid catalyzed by a phosphine free manganese complex: investigation and mechanistic insights

Léval, Alexander; Agapova, Anastasiya; Steinlechner, Christoph; Alberico, Elisabetta; Junge, Henrik; Beller, Matthias

doi:10.1039/c9gc02453k

“…From here, the activity of a couple of bidentate PPand NN-type Mn complexes (Mn-10 and Mn-11), earlier reported for the hydrogenation of nitriles and the dehydrogenation of formic acid, were evaluated. [56,57] However, both of these catalysts failed at deconstructing PU-1. Finally, the manganese complex precursor [Mn(CO) 5 Br] and the free ligand ( iPr MACHO) were tested, resulting in no MDA formation (see the Supporting Information, Section 6a for full details).…”

Section: Resultsmentioning

confidence: 98%

Evaluation of Manganese Catalysts for the Hydrogenative Deconstruction of Commercial and End‐of‐Life Polyurethane Samples

Gausas

¹

,

Donslund

²

,

Kristensen

³

et al. 2021

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Polyurethane (PU) is a thermoset plastic that is found in everyday objects, such as mattresses and shoes, but also in more sophisticated materials, including windmills and airplanes, and as insulation materials in refrigerators and buildings. Because of extensive inter-cross linkages in PU, current recycling methods are somewhat lacking. In this work, the effective catalytic hydrogenation of PU materials is carried out by applying a catalyst based on the earth-abundant metal manganese, to give amine and polyol fractions, which represent the original monomeric composition. In particular, Mn-Ph MACHO is found to catalytically deconstruct flexible foam, molded foams, insulation, and end-of-life materials at 1 wt.% catalyst loading by applying a reaction temperature of 180 °C, 50 bar of H 2 , and 0.9 wt.% of KOH in isopropyl alcohol. The protocol is showcased in the catalytic deconstruction of 2 g of mattress foam using only 0.13 wt.% catalyst, resulting in 90 % weight recovery and a turnover number of 905.

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“…[22][23][24][25][26][27][28][29][30][31] Manganese complexes have also been reported to be active in this reaction, as reported by Boncella, Tondreau, et al and Beller et al. [32][33][34] The activity of other 3d metals was assessed over the past few years, using nickel (Junge, Enthaler et al and Parkin et al), 35,36 copper (Correa et al), 37 and cobalt (Beller et al and Onishi et al). 38,39 Group 13 compounds were also investigated, namely aluminium by the group of Berben in 2014, 40 and boron by our group.…”

mentioning

confidence: 84%

Additive-Free Formic Acid Dehydrogenation Catalyzed by a Cobalt Complex

Lentz¹,

Aloisi²,

Thuéry³

et al. 2021

Preprint

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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 4000 h-1 and a turnover number (TON) of 454, without the need for bases or additives. A mechanistic study reveals that the ligand has a non-innocent behaviour due to intermolecular hydrogen bonding, which is influenced by the concentration of formic acid

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“…[22][23][24][25][26][27][28][29][30][31] Manganese complexes have also been reported to be active in this reaction, as reported by Boncella and Tondreau et al, and Beller et al. [32][33][34] The activity of other 3d metals was assessed over the past few years, using nickel (Junge, Enthaler et al and Parkin et al), 35,36 copper (Correa et al), 37 and cobalt (Beller et al and Onishi et al). 38,39 Group 13 compounds were also investigated, namely aluminium by the group of Berben in 2014, 40 and boron by our group.…”

mentioning

confidence: 85%

Additive-Free Formic Acid Dehydrogenation Catalyzed by a Cobalt Complex

Lentz¹,

Aloisi²,

Thuéry³

et al. 2020

Preprint

0

View full text Add to dashboard Cite

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 4000 h-1 and a turnover number (TON) of 454, without the need for bases or additives. A mechanistic study reveals that the ligand has a non-innocent behaviour due to intermolecular hydrogen bonding, which is influenced by the concentration of formic acid

show abstract

Hydrogen production from formic acid catalyzed by a phosphine free manganese complex: investigation and mechanistic insights

Abstract: Formic acid dehydrogenation (FAD) is considered as a promising process in the context of hydrogen storage.

Cited by 76 publications

References 49 publications

Evaluation of Manganese Catalysts for the Hydrogenative Deconstruction of Commercial and End‐of‐Life Polyurethane Samples

Evaluation of Manganese Catalysts for the Hydrogenative Deconstruction of Commercial and End‐of‐Life Polyurethane Samples

Additive-Free Formic Acid Dehydrogenation Catalyzed by a Cobalt Complex

Additive-Free Formic Acid Dehydrogenation Catalyzed by a Cobalt Complex

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