Progress toward Lignin Valorization via Selective Catalytic Technologies and the Tailoring of Biosynthetic Pathways

Biomass has received significant attention in the 21st century regarding its ability to become an alternative source of carbon for the production of strategic chemicals and fuels. Although multiple approaches for the selective valorization of biorefinery carbohydrates are known, processes of similar selectivity for the valorization of lignin are scarce, which can be attributed to its heterogeneity arising from its biosynthesis, as well as methods used for its isolation within the biorefinery. This perspective highlights advances within the last six years toward lignin valorization in the areas of thermochemical transformations, oxidations, reductions, and the tailoring of the lignin biosynthetic pathway in an effort to produce high-value chemicals and fuels. Should these current hurdles be addressed, significant progress can be made toward the realization of biomass replacing petroleum in meeting the world's energy and chemical needs.