Interfaces in Materials for Hydrogen Power Engineering

Abstract

Hydrogen power engineering is based on the production of hydrogen and subsequent oxidation of it to generate electrical energy. Using the example of ion-exchange membranes, catalysts for low-temperature fuel cells, and catalysts for alcohol steam reforming, the features of the transfer, catalysis, and electrocatalysis in hydrogen power engineering are discussed. Particular attention is paid to the role of interfaces. The occurrence of transport processes in ion-exchange membranes is determined by a system of pores and channels that are formed in the membranes owing to self-organization processes. The main selective transport of counterions occurs in a thin Debye layer at the interface between the polymer and the water solution that fills the pores. The transport of gases in these systems occurs through an electrically neutral solution localized in the center of the pores; it can be controlled by introducing nanoparticles into the pores. Catalytic processes in fuel cells occur at the interface between three phases, namely, the catalyst, the support, and the proton-conducting component. The role of the support in the stabilization and enhancement of the power of fuel cells is discussed. Despite the significant difference, the laws governing the catalytic processes of alcohol steam reforming are similar to those of fuel cells in many respects. The nature of metal catalysts is responsible for the preferred direction of the process, whereas the nature of the support largely determines the catalyst performance.