Vol 92, No 6 (2023)
Articles
Influence of surface groups on the properties of disperse systems
Abstract
Published data on the influence of surface groups on various properties of disperse systems are integrated and analyzed. The preparation of these systems is considered in relation to activated carbon. The discussion addresses the effect of redox reactions of surface groups on the energy efficiency of electrochemical supercapacitors, operation of capacitive deionization units for water desalination, and functioning of redox capacitors based on organic monomers. It is shown that very high energy and power characteristics of lithium ion capacitors are based on the redox reactions of lithium-containing surface groups of highly dispersed graphene electrodes. The effect of surface groups on the self-discharge of electrochemical supercapacitors with activated carbon-based electrodes is demonstrated. The prospects for the production of drinking water by capacitive deionization using mosaic cation/anion exchange membranes are evaluated. The practically important inversion of sulfo groups relative to the polymer chain in the catalyst layers of fuel cells with proton exchange membranes is noted.The bibliography includes 181 references.
Uspehi himii. 2023;92(6):RCR5080
RCR5080
Polymer materials for solving actual problems of membrane gas separation
Abstract
Membrane gas separation using polymeric membranes is one of rapidly developing energy-conserving technologies. This review describes the scope of membrane gas separation problems and demonstrates the relevance of membrane methods for their solution. The basic concepts and regularities of diffusion gas transfer and principles and characteristics of membrane gas separation are considered. The main physicochemical approaches to the selection of membrane materials considering both the properties of the gas—polymer system and the structure and physical properties of polymers are discussed. The considered issues are combined within a common approach to substantiate the choice of both existing commercial polymers and advanced polymeric materials to address important gas separation problems such as separation of air components; carbon dioxide, hydrogen and helium recovery from natural and industrial gas mixtures; and separation of a nitrogen and methane mixture. The avenues of development of the membrane materials science to solve each of the mentioned problems of membrane gas separation are demonstrated. The review is intended for specialists in the synthesis and physics of polymers for planning the research and assessing the applicability of polymeric materials for various practical gas separation problems and for specialists in the membrane materials science and membrane technology. The bibliography includes 165 references.
Uspehi himii. 2023;92(6):RCR5083
RCR5083
Mechanisms of catalytic electrochemical reactions of oxygen reduction (ORR) and carbon dioxide reduction (CO2RR)
Abstract
The review covers the electrochemical reactions of oxygen reduction (ORR) and carbon dioxide reduction (CO2RR) with a focus on mechanisms, structure of intermediates, and thermodynamics of reactions. The ORR on metal,heteroatom-codoped nanocarbon substrates as catalysts is a promising source of pure electrical energy. CO2RR, being a synthetic analogue of the photosynthesis reaction, has great potential for the generation of partial or complete reduction products. Theoretical insights into the mechanism and kinetics of CO2RR are just being developed, so the systematization of advances and emerging issues is a necessary step for further progress.The bibliography includes 242 references.
Uspehi himii. 2023;92(6):RCR5085
RCR5085