Catalytic conversion of glycerol to formic acid under mild condition over an iron-based catalytic system

Abstract

Glycerol, produced in large amounts as the main by-product of biodiesel production from biomass, has great potential to be converted into formic acid which is a potential hydrogen carrier. This research aims to evaluate the performance of an iron-based catalytic system in the oxidation process of glycerol to formic acid. The methods used include preparing an iron (II) oxalate catalyst, determining the reaction medium and reaction time for glycerol oxidation, optimizing the conditions of the glycerol oxidation process, and analysing the glycerol oxidation products. Optimization of process conditions includes the influence of temperature, substrate/catalyst molar ratio, and oxidant/substrate molar ratio. The research showed that water was a better reaction medium for glycerol oxidation, with a reaction time of 240 minutes. Oxidation of glycerol with an iron (II) oxalate catalyst can produce formic acid products with the best results obtained at pH 5, temperature 50°C, substrate/catalyst molar ratio of 100, and oxidant/substrate molar ratio of four with 83.18% converted glycerol. The yield and selectivity of formic acid were 47.77% and 57.43% respectively. These results indicate that the iron-based catalytic system has the potential to be an effective catalytic system for glycerol oxidation under mild conditions.