Selective oxidation of furfural and 5-methylfurfural under green conditions

Bio-renewable fuels and chemicals are becoming increasingly important as humans continue to deplete petroleum resources. An important aim for the future is to develop new processes from biomass and use it as a versatile feedstock because it is the largest carbon resources on earth. The increasing cost of fossil fuels and concerns about their environmental impact are accelerating the transition to a biomass-based economy. While fuel production from biomass has gained much attention, the use of renewable resources is also very important for the production of chemicals. Typically, chemical intermediates have a much higher value than fuels. These intermediates, traditionally derived from fossil fuels, can be further transformed into solvents, polymers, and specialty chemicals. The aim of this work is to investigate the catalytic transformation of furfural and 5-methyl furfural, two important intermediates obtained from biomass upgrading. It is more particular focused on their oxidation using green conditions and heterogeneous catalysts. In literature many processes for the catalytic oxidation of furfural are reported. In this process the highly desired product is maleic acid, but many other interesting products like furoic acid and furanone can be also obtained depending on the catalytic system used (and/or conditions). The reactivity of 5-methyli furfural is still instead quite unknown. The first part of the thesis screened different types of heterogeneous catalysts to produce selectively furoic acid or maleic acid from furfural and 5-methyl furoic acid from 5-methyl furfural. Very often this type of reactions hides several problems and specific conditions must be applied to improve furfural and 5-methyl furfural conversion, overall carbon balance, yield and selectivity to the desired products and this is was the aim of the second part of the study.