Glycerol conversion into added-value products on Ni-Cu based catalysts: Investigating mechanistic variations via catalyst modulation

Abstract

Glycerol (propane-1,2,3-triol), a byproduct of biodiesel production, serves as a valuable precursor for numerous products including hydrogen, propylene glycol (propane-1,2-diol), propane-1,3-diol, lactide, acrolein, hydroxyacetone, pyruvaldehyde, acetaldehyde, ethylene glycol, glyceraldehyde, lactic acid, acetic acid, formic acid, glyceric acid, tartronic acid, oxalic acid, glycolic acid, glyoxylic acid, and pyruvic acid, among others. Utilizing glycerol for the production of these diverse compounds not only enhances the sustainability of biodiesel production but also contributes to the economic viability of the entire process.The primary challenge in realizing the conversion of glycerol into the aforementioned chemicals lies in the need for catalysts with adequate activity, selectivity, and stability for the various processes involved. To address this, researchers have frequently employed cost-effective Ni-Cu-based catalysts in studies focused on glycerol conversion. These catalysts can be effectively modified to adjust their activity, selectivity, and stability, thereby enabling the conversion of glycerol into valuable products. This review provides a comprehensive overview of recent achievements related to Ni-Cu catalysts utilized in glycerol conversion to valuable products. It explores and discusses general principles governing the catalytic properties of these catalysts. Special attention is paid to the modification of the reaction mechanisms by varying catalyst morphology and composition or adjusting reaction conditions. These modifications play a crucial role in achieving the desired products effectively. The knowledge gained on modifying the reaction mechanism by modulating Ni–Cu catalysts can be further utilized in the design of catalysts with improved characteristics for glycerol conversion.