Mechanistic Insights into Photocatalytic Conversion of Biomass‐Derived Platform Molecules

Photocatalytic conversion of biomass‐derived platform molecules provides a promising route to store intermittent solar energy as clean chemical energy, enabling the sustainable production of high‐value chemicals from abundant, low‐cost biomass. However, achieving high selectivity and conversion efficiency remains challenging due to the inherent complexity of multistep interfacial reaction pathways. This review concludes recent advances in mechanistic investigations that encompass all crucial processes, including active species evolution, intermediate transformation, charge transfer, and chemical bond cleavage/reformation, employing advanced experimental methods, including electron paramagnetic resonance spectroscopy, radical quenching, isotope labeling, and in situ Fourier transform infrared spectroscopy. The applicability, sensitivity, and limitations of these techniques are critically evaluated across diverse reaction environments. Finally, we outline key challenges, such as limited temporal resolution, and discuss prospects for integrating complementary operando techniques with data‐guided mechanistic modeling.