Conversion of CO 2 from Air into Methanol Using a Polyamine and a Homogeneous Ruthenium Catalyst

Jotheeswari Kothandaraman, Alain Goeppert, Miklos Czaun, George A. Olah^*, and G. K. Surya Prakash^*

Loker Hydrocarbon Research Institute and Department of Chemistry, University of Southern California, University Park, Los Angeles, California 90089-1661, United States

J. Am. Chem. Soc., Article ASAP

DOI: 10.1021/jacs.5b12354

Publication Date (Web): December 29, 2015

Copyright © 2015 American Chemical Society

*olah@usc.edu., *gprakash@usc.edu.

http://pubs.acs.org/doi/10.1021/jacs.5b12354

Abstract

A highly efficient homogeneous catalyst system for the production of CH₃OH from CO₂ using pentaethylenehexamine and Ru-Macho-BH (1) at 125–165 °C in an ethereal solvent has been developed (initial turnover frequency = 70 h^–1 at 145 °C). Ease of separation of CH₃OH is demonstrated by simple distillation from the reaction mixture. The robustness of the catalytic system was shown by recycling the catalyst over five runs without significant loss of activity (turnover number > 2000). Various sources of CO₂ can be used for this reaction including air, despite its low CO₂ concentration (400 ppm). For the first time, we have demonstrated that CO₂ captured from air can be directly converted to CH₃OH in 79% yield using a homogeneous catalytic system.