The availability and multifunctionality of lignin makes it a desirable, renewable alternative to petroleum for specialty and bulk chemicals. However, recovering lignin from black liquor is expensive, thus lowering its prospect as a raw material source. Direct conversion of unwashed lignin (UL) to chemicals eliminates unit operations and reaction steps, which makes it a more likely feedstock. We compared the selective oxidation of lignin and UL to produce carboxylic acids over vanadium pyrophosphate (VPP), HZSM-5 zeolite, and VPP/HZSM-5 catalysts at atmospheric pressure and varying temperature (from 140 to 650 degrees C), steam concentration (from 0 to 20%), and oxygen (from 0 to 15.5%). The main acids produced were formic acid, acetic acid, and malonic acid. VPP/HZSM-5 produced 5% more acids with UL compared to treated lignin. The catalytic reaction network comprises both anaerobic and aerobic pathways for oxidation-based valorization of free phenolic guaiacylglycerol-beta-guaiacyl ether (GG) and non-phenolic veratrylglycerol beta-guaiacyl ether (VG) model lignin compounds. The three main reaction types include selective catalytic oxidative depolymerization with interunit bond breakage (e.g., alkyl-O-aryl bonds), alkyl side chain modification (e.g., C-alpha-OH to C-alpha=O ketone), and aromatic ring oxidation and ring opening to produce benzoquinones and dicarboxylic acids.