In the range of 1820-1630 cm -1 of the unconjugated and conjugated carbonyl vibrations, a clear increase in intensity in the form of a broad band can be seen compared to the unmodified lignin. The reason for this is the introduction of different carbonyl functions into the lignin framework. The band position shifts on average from 1700 cm -1 to 1715 cm -1 (S2). Chen et al. showed in an experiment that bands with the same position and intensities occur in esterifications of lignin with different organic anhydrides, but this was also associated with an increase in intensity at 1210 cm -1 and 1265 cm -1 . According to the literature, these vibrations are associated with C-O stretching vibrations and C-H deformation vibrations in esters and ethers . While the intensities around 1715 cm -1 increase significantly, only a decrease in intensity can be observed at 1265 cm -1 , 1210 cm -1 and the broad band around 1145-1120 cm -1 . This decrease in intensity indicates a cleavage of the ether bonds, which are present in large numbers in the lignin, and which are degraded by the base influence. In various mechanochemical depolymerisation experiments on kraft lignin with alkaline additives, this was observed on several occasions . However, systematic mechanochemical experiments with solid hydrogen peroxide species are not represented to the best of our knowledge, as hydrogen peroxide is more commonly used in aqueous environments in modified Fenton reactions and there are few solid hydrogen peroxide carriers . In addition to the cleavage of ether bonds, alkaline hydrogen peroxide favours the formation of aldehyde, ketone and carboxyl functions via various mechanisms . The lignin skeleton can also be degraded in some cases via ring cleavage. An indication of this can be provided by the small decrease in absorption at 1510 cm -1 , which is one of the characteristic ring vibrations .