Valorization of levulinic acid over non-noble metal catalysts: challenges and opportunities

Levulinic acid (LA), easily derived from cellulose via an acid catalytic process, is an attractive biomass-derived platform chemical which can be converted into various valuable chemicals, and LA valorization is an important component in biomass transformation. For LA conversion, non-noble metal catalytic systems have attracted significant attention due to their low cost compared with noble metals, and much progress has been achieved in recent years. This review focuses on the efficient and selective transformation of LA into a diverse range of products in non-noble metal catalytic systems. A reasonable outlook is presented in the last part of the review to highlight the challenges and opportunities associated with LA upgrading over non-noble metal catalysts.