In this study, oxidative depolymerization in an alkaline aqueous media was applied to seven lignin samples with varying botanical origins and pulping and extraction techniques, either in the presence or absence of a solid copper catalyst and I say kudos to the researchers that carried out this timely research.

Overall, the manuscript is well complied, the figures were sharp enough, and the experimental data is appreciable. However, I believe the language can still be polished and must be addressed by the authors with utmost attention before considered for publication.

Once the above comment is addressed properly, the manuscript can be accepted for publication in RSC Sustainability.