Glycerol to lactic acid conversion by NHC-stabilized iridium nanoparticles
Journal article, 2018

Hydrogen reduction of an Ir(I) complex featured by a bulky N-heterocyclic carbene (NHC) ligand in dichloromethane gave small-sized (1.8 nm) Ir nanoparticles (NPs) decorated with NHC ligands (IrNHC). 1,4-Dioxane solutions of the latter particles were successfully applied to convert glycerol into lactic acid in the presence of NaOH (i.e. 1 mol equivalent with respect to glycerol). IrNHC showed an atom-related TOF value of almost 104 h−1, an almost exclusive formation of liquid reaction products, a high selectivity for lactic acid (93.0%) and a complete recyclability in air atmosphere. Attempts to synthesize analogous NHC-stabilized Ir NPs on a high surface area carbon support (CK) by reducing the same Ir(I) precursor, supported onto CK, prior to the hydrogen reduction in water, gave almost naked CK-supported Ir NPs (1.4 nm). Their catalytic activity tested for the same reaction in water as reaction medium, exhibited much lower catalytic activity (4 × 103 h−1), a lower percentage of liquid reaction products (i.e. 27.0% of the converted glycerol) and a lower selectivity for lactic acid compared to IrNHC.

Iridium nanoparticles

1,4-Dioxane

NHC-ligand

Glycerol

Lactic acid

Author

Werner Oberhauser

Institute of Chemistry of Organometallic Compounds (ICCOM)

National Research Council of Italy (CNR)

Claudio Evangelisti

Consiglo Nazionale Delle Richerche

Institute of Molecular Science and Technologies

A. Liscio

Consiglo Nazionale Delle Richerche

Istituto per la Sintesi Organica e la Fotoreattività

Alessandro Kovtun

Consiglo Nazionale Delle Richerche

Istituto per la Sintesi Organica e la Fotoreattività

Yu Cao

Chalmers, Industrial and Materials Science, Materials and manufacture

Francesco Vizza

Consiglo Nazionale Delle Richerche

Institute of Chemistry of Organometallic Compounds (ICCOM)

Journal of Catalysis

0021-9517 (ISSN) 1090-2694 (eISSN)

Vol. 368 298-305

Subject Categories

Inorganic Chemistry

Other Chemical Engineering

Organic Chemistry

DOI

10.1016/j.jcat.2018.10.024

More information

Latest update

4/15/2019