Antioxidant-driven activity and stability enhancement in multiphase bicarbonate hydrogenation catalysis with a Ru-PNP pincer complex

• Published in: Journal of CO2 utilization Vol. 81; p. 102718
• Main Authors: Hirano, Makoto, Wada, Kazuhito, Matsuda, Hirokazu, Pidko, Evgeny A.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.03.2024; Elsevier
• Subjects: Antioxidant; Bicarbonate hydrogenation; Catalyst Stabilization; Multiphase system; Pincer complexes; Pincer complexes; Multiphase system; Bicarbonate hydrogenation; Antioxidant; Catalyst Stabilization
• ISSN: 2212-9820; 2212-9839
• DOI: 10.1016/j.jcou.2024.102718

Herein, we present a practical strategy to enhance the performance of a multiphase system for bicarbonate hydrogenation based on a molecular Ru-PNP pincer catalyst. This study demonstrates that the use of organic antioxidants not only mitigates catalyst degradation but also significantly boosts its intrinsic activity. This enables efficient catalyst recycling at ultra-low concentrations. Systematic screening and optimization of a range of organic antioxidants has identified TDTBP (tris(2,4-di-tert-butylphenyl) phosphite) as being exceptionally efficient in stabilizing and enhancing the performance of the Ru-PNP catalyst. With the optimized system an unprecedented integral turnover frequency (TOF) of 115,000 h−1 and a total turnover number (TTON) of 9.43×106 across four recycling tests were demonstrated, conducted at a reaction temperature of 90 ºC and H2 pressure of 50 bar. These findings represent a substantial advancement in sustainable formate/formic acid production, offering a scalable and highly efficient method suitable for industrial-scale application. [Display omitted] •Bicarbonate Hydrogenation using the Ru-PNP Pincer Complex Catalyst.•A multiphase system enables the separation from the product and reuse of the catalyst.•The application of antioxidants effectively stabilizes the catalyst, resulting in a significant enhancement of catalyst activity.•Utilization of antioxidants achieves maximum catalyst turnover frequency and total turnover number of up to 115,000 h−1 and 9.43×106, respectively.