CARBON DIOXIDE: PROPERTIES, SOURCES AND UTILIZATION METHODS

Environmental problems, such as climate change and global warming (the "greenhouse effect"), are associated with an increase in the concentration of carbon dioxide in the atmosphere. Reducing CO2 emissions is of great economic and environmental importance to humanity. At the same time, carbon dioxide is considered an ideal C-1 building block in organic synthesis for ease of availability, low cost, nontoxicity and inflammability. Cost-effective and environmentally friendly chemical processes using CO2 in the synthesis of valuable chemicals are one of the technological advances aimed reducing CO2 emissions into atmosphere. But, due to thermodynamic stability and chemical inertness, it is difficult to convert CO2 into valuable products using effective, selective and "green" catalysis under mild conditions. To overcome these barriers, several synthesis strategies have been developed using polyfunctional catalysts for CO2 conversion. Recent advances in the development of efficient, selective, and environmentally friendly catalytic processes using homogeneous and heterogeneous catalysts summarized in this review, show that CO2 activation is a necessary prerequisite for CO2 conversion, and usually consists of: the development of reliable catalysts for effective catalytic conversion of CO2 other than stoichiometric reactions; the design and selection of high-energy active substrates; development of polyfunctional catalysts with two or more active centers for synergistic activation of both CO2 and substrate. As expected, CO2 can be efficiently and selectively converted into valuable chemicals, fuels, and polymers through "green" catalysis processes. This material provides a review of the literature on the effects of carbon dioxide on global warming, sources of CO2 generation, and various methods used to convert carbon dioxide into important chemical products such as urea, salicylic acid, organic carbonates, methanol, polycarbonates, and organic cyclic carbonates