Catalytic Wet Oxidation of Ferulic Acid (A Model Lignin Compound) Using Heterogeneous Copper Catalysts

Abstract

Catalytic wet oxidation (CWO) of ferulic acid (a model lignin compound) was investigated at low temperature and pressure (100 °C, 172 kPa P O2). Nine homogeneous catalysts were screened at three different catalyst loadings. Homogeneous copper ions were observed to be the most active catalysts; various copper based heterogeneous catalysts were also prepared and tested. The most active catalyst was Cu−Ni−Ce−Al2O3; however, this catalyst also exhibited the highest extent of copper leaching. Cu−Mn−Al2O3 was the most stable catalyst tested and was second only to Cu−Ni−Ce−Al2O3 in terms of activity among nine heterogeneous catalysts studied. Heterogeneous catalytic activity compared with the activity due to leached metal ions was observed to be dominant for both of the above-mentioned catalysts.