In this study we have tested some alternative catalysts for oxygen reduction in an alkaline electrolyte (7M KOH). The catalysts tested were: CoTMPP, LaNiO3, Pt (for comparison), and MnO2. The electrodes were manufactured by the rolling method. The best electrodes made in this way were tested in a long run test, testing times ranging from 425 to 660 h. The decay in potential during the 660 h run was 0.041 mV/h. ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 129.100.58.76 Downloaded on 2014-09-29 to IP

The aim of our research has been to investigate the equilibrium state of electrochemical systems: half cells, fuel cells, and secondary and primary batteries. The analysis presented here is based on the use of a balance matrix theory. The same type of idea has already been used in computer programs for chemical systems, but here it is extended to electrochemical systems. A discharge equation is introduced, with the aid of which the electrochemical cells can be studied at various degrees of discharge. A simple model for electrostatic energy is presented, which enables us also to calculate the charges of the electrodes in the equilibrium state 9 The advantage of the approach presented here and the motivation for the analysis is that it is easily applicable to computational purposes, even to complicated systems with many phases and also with irreversible constraints. A brief summary of a computer program based on this theory is presented, and the use of the program is illustrated by some examples 9

The aim of the research has been a mathematical analysis of the phase rule and its role in solving the problem of minimizing the total free energy of the system. A special equilibrium problem is studied, where, in addition to the normal potential functions of the phases, the electrostatic energy of the system is taken into account. The electrostatic energy function is not homogeneous of the first degree with respect to the variables and therefore the phase rule becomes slightly modified. An equation for the maximum number of coexisting phases for the equilibrium problem of this kind is derived and it is illustrated by simple examples.

The second law of thermodynamics is presented in terms of the heat accumulation function. The meaning of the heat accumulation functions is illustrated by a practical example. The optimization problem of heat engines is formulated with the aid of the heat accumulation function at a very general level. As an example, we have studied a heat engine process where the heat input and output changes are limited by the finite heat capacity of the combustion air. We have obtained formulas for estimating the maximum efficiency for heat engines as a function of the ratio of the combustion heat and the heat capacity of the combustion air. Representative numerical examples are presented.