Photocatalytic Synthesis of High-Energy-Density Fuel: Catalysts, Mechanisms, and Challenges

High-energy-density liquid hydrocarbon fuels are generally synthesized using various chemical reactions to improve the performance (e.g., range, load, speed) of aerospace vehicles. Compared with conventional fuels, such as aviation kerosene and rocket kerosene, these liquid hydrocarbon fuels possess the advantages of high-energy-density and high volumetric calorific value; therefore, the fuels have important application value. The photocatalytic process has shown great potential for the synthesis of a diverse range of fuels on account of its unique properties, which include good efficiency, clean atomic economy, and low energy consumption. These characteristics have led to the emergence of the photocatalytic process as a promising complement and alternative to traditional thermocatalytic reactions for fuel synthesis. Extensive effort has been made toward the construction of catalysts for the multiple photocatalytic syntheses of high-energy-density fuels. In this review, we aim to summarize the research progress on the photocatalytic synthesis of high-energy-density fuel by using homogeneous and heterogeneous catalytic reactions. Specifically, the synthesis routes, catalysts, mechanistic features, and future challenges for the photocatalytic synthesis of high-energy-density fuel are described in detail. The highlights of this review not only promote the development of the photocatalytic synthesis of high-energy-density fuel but also expand the applications of photocatalysis to other fields.