An overview of catalysts for the hydrodeoxygenation reaction of model compounds from lignocellulosic biomass

The transport sector is in all probability the one that emits the greatest amounts of CO2 and other harmful gases into the atmosphere. Therefore, the emission of greenhouse gases from the combustion of fossil fuels must be significantly reduced to mitigate their harmful effects on the environment. In this sense, bio-fuels obtained from lignocellulosic biomass are a solution to partially replace fuels from petroleum. However, the biggest challenge facing the scientific community is to decrease the amount of oxygen in bio-fuels through catalytic hydrodeoxygenation (HDO) reactions. This review offers a broad perspective on the catalytic systems used so far in the HDO processes of model compounds present in bio-fuels, analyzing in detail the advantages and disadvantages of each system to give a vision towards the future.