Carbon Dioxide Conversion

Abstract A summary of the catalytic transformations of CO 2 is presented. The review is divided into five sections according to the broad categories of homogeneous, polymerization, heterogeneous, electro‐ and photochemical, and biological catalysis. The section on homogeneous catalysis focuses mainly on CO 2 hydrogenation and the coupling reactions between CO 2 and unsaturated hydrocarbons. The discussion on polymerization catalysis encompasses primarily the production of polycarbonates from CO 2 and epoxides. The heterogeneous catalysis of CO 2 is nearly entirely devoted to either the hydrogenation of CO 2 or the dry‐reformation of methane. Heterogeneous examples of homogeneous catalyses are also included. Electro‐ and photochemical catalyses are distinguished from each other by the source of the reducing electrons. These processes are further subdivided into those that occur via homogeneous catalysts and those that occur heterogeneously at an electrode or semiconductor surface. The section on biological catalyses discusses first the enzyme carbonic anhydrase, followed by CO 2 ‐assimilation pathways under both aerobic and anaerobic conditions, and it covers both naturally occurring and biomemetic systems.