Tailoring the electronic structure and acid–base properties of MgO by Ce doping promotes biomass-derived formic acid production at room temperature†

Abstract

Biomass-based monosaccharide oxidation for formic acid production is significant due to its potential to provide a sustainable, bio-based alternative to traditional fossil fuel-derived methods of formic acid synthesis. In this study, we developed a Ce–MgO catalyst by incorporating Ce to enhance the oxidation of glucose to formic acid. Compared to unmodified MgO, the Ce–MgO catalyst exhibits an increased number of basic sites and higher charge densities at the Mg and O sites. These modifications facilitate the selective dissociation of hydrogen peroxide to form ˙OOH species and enhance the adsorption of ˙OOH at the MgO sites. The electron-rich nature of these Mg(OH)(OOH) active sites lowers the energy barrier for the C–C cleavage and oxidation reaction through more efficient electron transfer. Consequently, the reaction can be conducted at room temperature, achieving a 97.34% conversion of glucose and 93.65% yield of formic acid, which represents the highest performance among all glucose oxidation catalysts for formic acid production. Furthermore, the Ce–MgO catalyst demonstrated its efficacy in catalyzing the oxidation of a mixed sugar solution derived from corncob, achieving a formic acid yield of 49.13% at 30 °C. Additionally, the formic acid produced via this process enables in situ hydrogen production at room temperature, highlighting an effective and sustainable approach for generating green hydrogen from biomass.