Research progress of nano-catalysts in the catalytic conversion of biomass to biofuels: Synthesis and application

In recent years, fossil fuels have caused serious environmental pollution and will eventually be exhausted. The development of sustainable environmentally friendly fuels is an inevitable choice to ensure the sustainable development of society. As an extensive natural resources on the earth, biomass is the organic energy pool of solar energy, which can be changed over into various biofuels through various pathways, for example, biodiesel, biohydrogen, and bioethanol. To improve the yield and reduce its consumption, catalysts play a crucial role in the conversion process. However, traditional catalysts have various disadvantages. To solve this problem, the development of nanoscience and technology has widely penetrated the field of catalytic research, specifically, nano-catalysts. Nano-catalysts have unique nanostructures and properties that ordinary catalysts do not have, which determine the high catalytic performance and selectivity of nano-catalysts. At present, there are numerous methods to prepare nano-catalysts, such as co-precipitation synthesis, hydrothermal synthesis, sol–gel synthesis, etc., all of which have advantages and disadvantages. Hence, this paper summarizes the deficiencies of traditional catalysts, and focuses on the application of nano-catalysts in biomass conversion to biofuels and their synthesis methods. Meanwhile, renewable resources can be used in the future to develop multifunctional and efficient nano-catalysts to improve resource utilization and reduce catalyst usage.