Light-Driven Oxidation of Light Alkanes: Current Challenges and Prospects

The current energy crisis and environmental concerns inspire researchers to develop new strategies to reinvent the conventional oil-based energy system. Shale gas, a mixture of light alkanes including methane, ethane, propane, and butane, can serve as an alternative to oil for producing value-added chemicals. Nevertheless, the conventional conversion of light alkanes requires high temperature due to the chemical inertness of C-H bond, which suffers from intensive energy consumption and challenges including the control of target product's selectivity and the long-term stability of catalyst. Addressing these challenges demands the innovation of sustainable catalytic systems with a good balance of activity, selectivity, and stability. Photocatalysis has recently attracted great interest in industry since it can harvest solar energy to trigger C-H activation at room temperature, being a clean method for the oxidation of light alkanes. Over past decades, great efforts have been devoted to the light-driven oxidation of light alkanes. Nevertheless, light-driven processes are limited by disadvantages including low productivity, tricky photon-electron-phonon interactions, and ultraviolet light dependence, which restrict their practical applications. Our group has contributed a series of advances in the light-driven oxidation of methane, ethane and propane to value-added chemicals via the precise control of interfacial structures of photocatalysts. This Account mainly focuses on the three key dimensions: (i) photothermal-induced oxidation of light alkanes, (ii) photocatalytic oxidation of light alkanes, and (iii) integrating photothermal-photocatalysis for the oxidation of light alkanes. It also confronts the current challenges in this field and proposes feasible strategies for addressing those issues. Although various products have been obtained via light-driven oxidation of methane at room temperature, future investigations should be closely oriented toward practical application. In this regard, special attention should be paid to the following aspects: (i) enhancing the utilization of visible and near-infrared light, (ii) balancing the correlation of activity-selectivity--stability, and (iii) investigating light-driven oxidation of ethane, propane, and butane.