An innovative light assisted production of acetic acid from CO and methanol: a first photocatalytic approach using a reusable cobalt() molecular hybrid at atmospheric pressure

• Published in: Green chemistry : an international journal and green chemistry resource : GC 2021-11, Vol.23 (22), p.948-96
• Main Authors: Saini, Sandhya, Samal, Pragnya paramita, Krishnamurty, Sailaja, Ray, Anjan, Jain, Suman L
• Format: Article
• ISSN: 1463-9262; 1463-9270
• DOI: 10.1039/d1gc02728j

Acetic acid is an important commodity chemical that is produced either by fermentation processes, or more commonly, through chemical routes such as methanol carbonylation with CO and H 2 , acetaldehyde oxidation, or hydrocarbon oxidation. More recently, methanol hydrocarboxylation with CO 2 and H 2 under thermal catalytic conditions has attracted interest. The synthesis of acetic acid from easily available CO 2 is of great significance yet rarely reported. The present paper describes the first photocatalytic approach for the synthesis of acetic acid from methanol and CO 2 under ambient reaction conditions without using molecular hydrogen. The maximum conversion of methanol achieved is 60% with a selectivity of 81% towards acetic acid using an octa-sulfur bound cobalt phthalocyanine (CoPc/S8) photocatalyst without an additional sacrificial electron donor. Product analysis, controlled experiments and DFT calculations suggest the formation of methylene carbene as a reactive intermediate. The developed methodology represents a potentially exciting approach for synthesizing acetic acid utilizing CO 2 in a sustainable manner. Acetic acid is an important commodity chemical that is produced either by fermentation processes, or more commonly, through chemical routes such as methanol carbonylation with CO and H 2 , acetaldehyde oxidation, or hydrocarbon oxidation.