*Review* **CO2—A Crisis or Novel Functionalization Opportunity?**

**Daniel Lach \*, Jaroslaw Polanski and Maciej Kapkowski**

> Institute of Chemistry, Faculty of Science and Technology, University of Silesia, Szkolna 9, 40-006 Katowice, Poland; polanski@us.edu.pl (J.P.); maciej.kapkowski@us.edu.pl (M.K.) **\*** Correspondence: daniel.lach@us.edu.pl; Tel.: +48-32-259-9978

**Abstract:** The growing emission of carbon dioxide (CO2), combined with its ecotoxicity, is the reason for the intensification of research on the new technology of CO2 management. Currently, it is believed that it is not possible to eliminate whole CO2 emissions. However, a sustainable balance sheet is possible. The solution is technologies that use carbon dioxide as a raw material. Many of these methods are based on CO2 methanation, for example, projects such as Power-to-Gas, production of fuels, or polymers. This article presents the concept of using CO2 as a raw material, the catalytic conversion of carbon dioxide to methane, and consideration on CO2 methanation catalysts and their design.

**Keywords:** carbon dioxide (CO2); carbon monoxide (CO); CO2 feedstock; methanation; catalyst; catalysis; photocatalysis; Power-to-Gas; catalyst design; heterogenous catalysts database
