Philosophiae Doctor - PhD / Maleic acid (MA) is a key intermediate for the synthesis of polyester resins, surface coatings, lubricant additives, plasticizers, copolymers, pharmaceuticals and agricultural chemicals. The current industrial production of MA is an energy-intensive gas-phase oxidation process of n-butane. The dwindling fossil resources and environmental issues have brought about a worldwide paradigm shift from fossil feedstocks to biomass resources for the sustainable production of fuel and chemicals. Furfural (FFR) and 5-hydroxymethylfurfural (HMF) are excellent biomass-derived platform chemicals, which present an alternative route for the production of renewable bio-based MA. There has been considerable success achieved in the oxidation of furfural and HMF to maleic acid and maleic anhydride with different catalysts in recent years.