A comparative performance of heterogeneous catalyst derived from diatomaceous earth, empty fruit bunch, and montmorillonite treated by acid and metal oxide for ethyl lactate production

Background: Currently, the rising demand for green chemistry and sustainable development encourages the creation and use of eco-friendly resources (industrial and agricultural wastes) for the production of high-value substants. In this study, solid-acid heterogenous catalysts derived by diatomaceous earth (DE), empty fruit branch (EFB), and montmorillonite (MMT) treated by sulfuric acid, phosphoric acid, and tungsten metal, respectively, were examined. Microwave-induced radiation was then used to improve both the DE and EFB surface.Methods: All modified catalysts were accordingly used to produce ethyl lactate by esterification. Characteristics of sulfonated diatomaceous earth (DE-AC), phosphorous treated empty fruit branch (EFB-AC), and tungstensupported montmorillonite (W/MMT) were analyzed using FTIR, XPS, NH3-TPD, XRD, SEM-EDX, BET, and TGA in order to examine their physical and chemical characteristics. Significant findings: The DE-AC and W/MMT showed a high potential for usage as solid acid catalysts, containing 2981 and 1298 mu mol/g of the total acid site, respectively. The yields of ethyl lactate for DE-AC, W/MMT, and EFB-AC were 58.55, 47.56, and 32.75%, respectively. Furthermore, DE-AC and W/MMT exhibit outstanding reusability for five consecutive cycles, indicating their potential as solid catalysts for ethyl lactate synthesis.

Automated summary

This study examined the application of solid-acid heterogeneous catalysts derived from diatomaceous earth (DE), empty fruit branch (EFB), and montmorillonite (MMT) for esterification reactions. The modified catalysts were analyzed to determine their physical and chemical characteristics. It was found that DE-AC and W/MMT showed high potential as solid acid catalysts for the synthesis of ethyl lactate.