Executive Summary : | The rapid increase in anthropogenic carbon dioxide is a significant concern, as atmospheric concentrations will continue to rise due to fossil fuel consumption. Hydrocarbon fuels, such as petroleum, natural gas, and coal, provide over 80% of energy, but their combustion also leads to environmental pollution and health impacts. Higher atmospheric CO2 levels result in an atmosphere that better retains heat, acting as the boundary condition for global heating. suggestions include sequestering carbon dioxide, but the ability to store billion tons of carbon emitted annually is questionable. Recycling carbon dioxide into a high-energy content fuel suitable for existing hydrocarbon-based energy infrastructure is an attractive option, but it is energy-intensive and only useful if a renewable energy source can be used. Major efforts are being made to develop sustainable and renewable energy sources, with solar energy being an attractive approach. The production of hydrocarbons by this route would be sustainable, environmentally friendly, and allow for the use of existing energy infrastructure. Photocatalysts are essential for efficient reactions, as solar radiation is absorbed by them, exciting electrons and holes involved in chemical reactions. In the past three decades, the ability to manipulate and characterize metal clusters and nanoparticles has increased, but a fundamental understanding of their properties as a function of size, shape, and composition remains to be achieved. Computational materials science can play an important role in this context, complementing experimental investigations. |