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

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.