Status and perspectives of CO2 conversion into fuels and chemicals by catalytic, photocatalytic and electrocatalytic processes.

A review. This review highlights recent developments and future perspectives in carbon dioxide usage for the sustainable prodn. of energy and chems. and to reduce global warming. We discuss the heterogeneously catalyzed hydrogenation, as well as the photocatalytic and electrocatalytic conversion of CO2 to hydrocarbons or oxygenates. Various sources of hydrogen are also reviewed in terms of their CO2 neutrality. Technologies have been developed for large-scale CO2 hydrogenation to methanol or methane. Their industrial application is, however, limited by the high price of renewable hydrogen and the availability of large-vol. sources of pure CO2. With regard to the direct electrocatalytic redn. of CO2 to value-added chems., substantial advances in electrodes, electrolyte, and reactor design are still required to permit the development of com. processes. Therefore, in this review particular attention is paid to (i) the design of metal electrodes to improve their performance and (ii) recent developments of alternative approaches such as the application of ionic liqs. as electrolytes and of microorganisms as co-catalysts. The most significant improvements both in catalyst and reactor design are needed for the photocatalytic functionalization of CO2 to become a viable technol. that can help in the usage of CO2 as a feedstock for the prodn. of energy and chems. Apart from technol. aspects and catalytic performance, we also discuss fundamental strategies for the rational design of materials for effective transformations of CO2 to value-added chems. with the help of H2, electricity and/or light. [on SciFinder(R)]