Biomass is considered one of the alternative resources with the greatest
potential to compete both as fuels and as chemical intermediates. Biomass-derived
molecules like glucose, xylose, HMF, and levulinic acid can be converted to valueadded chemicals via dehydration, oxidation, isomerization, reforming, and aldol
condensation processes using heterogeneous catalysts. The drawbacks of homogeneous
catalysts are their low solvent solubility, susceptibility to breakdown under oxidation
conditions, and requirement for product separation. Biomass contains a high amount of
water, and the formation of water as a byproduct during transformation is a significant
obstacle to reaction. Therefore, aqueous phase reaction using heterogeneous catalysts is
of major interest. There have been reports of studies employing expensive noble
transition metals as catalysts. Non-noble metal oxides are more widely available, less
expensive, and have greater thermal stability and poisoning resistance than noble
metals. In this chapter, we discuss some noble and non-noble metal heterogeneous
catalysts. Heterogeneous metal catalyst involves single metal, bimetallic catalysts,
metal oxide, spinel, perovskites, etc.
Keywords: Aqueous phase, Biomass, Heterogeneous catalyst, Intermediate, Noble metals.
