Review of the Development of Heterogeneous Catalysts for Liquid and Vapor Phase Hydrogenolysis of Glycerol to Propylene Glycol (1,2-Propanediol): State-of-the-Art and Outlook

Abstract

In the last two decades, various glycerol value addition techniques have been developed and discussed in the literature. Among all these processes, conversion of glycerol to 1,2-propanediol (1,2-PDO) has been recognized as one of the promising and commercially attractive glycerol value addition routes. This review is an attempt to scan out the progress in catalysts design and development for liquid and vapor phase glycerol hydrogenolysis for the production of 1,2-PDO. The development of supported and mixed metal oxide catalysts with their novel catalytic characteristics for glycerol conversion and 1,2-PDO selectivity has been scrutinized systematically. It was observed that among the nonnoble metal catalysts, Cu-based catalysts have shown promising activity toward 1,2-PDO; however, their stability is an issue. Among noble metals, Pt-and Ru-based catalysts were reported active for glycerol conversion. Comparatively, catalysts composed of Pt, Ru, Pd as a noble metal, and Cu as a non-noble metal have resulted in higher catalytic activity and 1,2-PDO selectivity. This review also summarizes different reaction pathways for hydrogenolysis of glycerol to 1,2-PDO, the effect of additives (solid acid and base), and methods of catalyst preparation on the catalyst performances. Further, glycerol hydrogenolysis with in situ H 2 production by glycerol reforming or by chemical transfer hydrogen using various hydrogen donors and the effect of different solvents on the glycerol hydrogenolysis process are also discussed. Reaction kinetic models are also included at the end.

Nickel‐Tin Nanoalloy Supported ZnO Catalysts from Mixed‐Metal Zeolitic Imidazolate Frameworks for Selective Conversion of Glycerol to 1,2‐Propanediol

“…The reaction pathway for glycerol hydrogenolysis is well known and it has been reported in the literature. [37] The detection of acetol as an intermediate in our study strongly suggests that the reaction route could be dehydration, followed by the hydrogenation mechanism. [4,38] The path for the formation of 1,2-PDO from glycerol is presented in Scheme 2.…”

Technological Insights on Glycerol Valorization into Propanediol through Thermocatalytic and Synthetic Biology Approaches

“…1,2-propanediol is conventionally synthesized through the hydrolysis of propylene oxide, a chemical that is generated by the processing of crude oil [74,75]. There are multiple approaches to producing propylene oxide, but one regularly used method is the chlorohydrin route, which produces a large amount of calcium chloride waste [74,76].…”

Virtual Special Issue on New Energy Developments at IIT Roorkee, India

“…The mechanism for the effective utilization of incident light to produce charge carriers that contribute to the PEC reduction of CO 2 along with challenges and future directions has been elucidated. Pandey and Biswas reviewed the progress in catalyst design/development for the production of 1,2-propanediol (1,2-PDO) employing liquid- and vapor-phase hydrogenolysis of glycerol. Different supported and mixed metal oxide catalysts for achieving higher glycerol conversion and better 1,2-PDO selectivity, various reaction pathways of the glycerol hydrogenolysis process, and in situ hydrogen production by glycerol reforming/chemical transfer hydrogen were examined and reported.…”