Recent advances in carbon dioxide selective hydrogenation and biomass valorization via single-atom catalysts

The utilization of fossil fuels has brought unprecedented prosperity and development to human society, but also caused environmental pollution and global warming triggered by excess greenhouse gases emission. For one thing, the excess emission of carbon dioxide (CO₂), which has a negative impact on global temperature and ocean acidity, needs to be controlled. For another, the depletion of fossil fuels will eventually force people to seek alternative carbon sources to maintain a sustainable economy. Thus, using renewable energy to convert CO₂ and biomass into value-added chemicals and fuels is a promising method to overcome urgent problems. The hydrogenation of CO₂ is very important to mitigate the greenhouse effect caused by CO₂, while biomass conversion can produce alternative renewable biofuels and green chemicals. As a kind of promising catalyst, heterogeneous single-atom catalyst (SAC) has received extensive attention in the past decades. SACs combine the advantages of homogeneous catalysts with uniform active sites and heterogeneous catalysts that are easily separable. In this review, we will give a comprehensive overview of the latest progress in CO₂ selective hydrogenation and biomass conversion via SACs.