This book presents the current status of CO₂ utilization from fundamental studies to industrial tests. With the development of renewable energy, carbon dioxide will become an important feedstock for the synthesis of fuels and chemicals, and CO₂ utilization must be the final solution for the carbon dioxide issues. This book discusses the effective techniques for activating inert carbon dioxide and various approaches for CO₂ conversion, such as homogeneous catalytic conversion, homogeneous catalytic conversion, heterogeneous catalytic conversion, photocatalytic conversion, electrocatalytic conversion, photo-thermal catalytic conversion, plasma-chemical/plasma-catalytic conversion, and bio-catalytic conversion. It also addresses the electronic and geometric structural effects of the supported catalyst on the activity and selectivity of the conversion of carbon dioxide. The significant effects from single atom catalyst to nanoparticle are also discussed, and process intensification in catalyst preparation and reaction is highlighted. Furthermore, this book contains chapters with theoretical studies, including functional theory, which has played an important role in the catalyst design, the explanation of the reaction mechanism, and in understanding the synergy of reaction and heat and mass transfer. Given its scope, this book appeals to a wider readership, especially for researchers in the field of CO₂ utilization.