Fast CO2 hydrogenation to formic acid catalyzed by an Ir(PSiP) pincer hydride in a DMSO/water/ionic liquid solvent system

Complex [IrClH{κP,P,Si-Si(Me)(C6H4–2-PiPr2)2}] (1) showed a remarkable catalytic activity for CO2 hydrogenation in a DMSO/H2O solvent system incorporating 1,2-dimethyl-3-butylimidazolium acetate ionic liquid (IL), producing 0.94 M formic acid with initial TOFs up to 1432 h−1 (CO2/H2 = 20/40 bar, 30...

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Detalhes bibliográficos
Autores: Webber, Rodrigo, Qadir, Muhammad I., Sola, Eduardo, Martín, Marta, Suárez, Elizabeth, Dupont, Jairton
Tipo de documento: artigo
Estado:Versão publicada
Data de publicação:2020
País:España
Recursos:Consejo Superior de Investigaciones Científicas (CSIC)
Repositório:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/233103
Acesso em linha:http://hdl.handle.net/10261/233103
Access Level:Acceso aberto
Palavra-chave:Ionic liquids
Solvent-cage
CO2 hydrogenation
Formic acid
Iridium
Descrição
Resumo:Complex [IrClH{κP,P,Si-Si(Me)(C6H4–2-PiPr2)2}] (1) showed a remarkable catalytic activity for CO2 hydrogenation in a DMSO/H2O solvent system incorporating 1,2-dimethyl-3-butylimidazolium acetate ionic liquid (IL), producing 0.94 M formic acid with initial TOFs up to 1432 h−1 (CO2/H2 = 20/40 bar, 30 °C). While the hydrogenation outcome followed dependences upon gas composition, pressure and temperature similar to those of other efficient systems in DMSO/H2O, the kinetic dependence upon catalyst loading revealed non-linear effects suggestive of relevant IL-catalyst interactions. NMR speciation studies identified two major complexes, [Ir(OCHO)(H){κP,P,Si-Si(Me)(C6H4–2-PiPr2)2}] (2) and [Ir(H)2{κP,P,Si-Si(Me)(C6H4–2-PiPr2)2}(DMSO)] (3), potentially responsible for catalytic cycling though inactive outside the current solvent system.