Hydrogen generation from the methanolysis of ammonia borane catalyzed by in situ generated, polymer stabilized ruthenium(0) nanoclusters

Abstract

Addressed herein is the detailed study on in situ generation of poly(N-vinyl-2-pyrrolidone) (PVP) stabilized ruthenium(0) nanoclusters and their catalysis in the methanolysis of ammonia borane (AB). PVP-stabilized ruthenium(0) nanoclusters with an average particle size of 2.4 ± 1.2 nm were generated in situ from the reduction of ruthenium(III) chloride during the methanolysis of AB in the presence of PVP at room temperature. The nanoclusters were characterized by UV–vis spectroscopy, TEM, XRD, XPS and FT-IR techniques. PVP stabilized ruthenium(0) nanoclusters are highly active and stable catalyst in hydrogen generation from the methanolysis of AB with a turnover frequency (TOF) value of 4017 h −1 and 71,500 turnovers over 25 h. Mercury poisoning experiments showed that the PVP-stabilized ruthenium(0) nanoclusters are the true heterogeneous catalyst in the methanolysis of AB. The report also includes the results of a detailed kinetic study on the hydrogen generation from the methanolysis of AB catalyzed by PVP stabilized ruthenium(0) nanoclusters investigating the effect of the catalyst concentration, substrate concentration, and temperature as well as the activation parameters of catalytic methanolysis of AB calculated from the kinetic data.