Journal of Power Sources 131 (2004) 107–111 Ionic activators in the electrolytic production of hydrogen—cost reduction-analysis of the cathode Milica P. Marˇ ceta Kaninski a,∗ , Aleksandar D. Maksi´ c a , Dragica Lj. Stoji´ c a , Š´ cepan S. Miljani´ c b a Laboratory of Physical Chemistry, Vinca Institute of Nuclear Sciences, P.O. Box 522, Belgrade 11001, Yugoslavia b Faculty of Physical Chemistry, University of Belgrade, P.O. Box 137, Belgrade 11001, Yugoslavia Abstract As recent technology progress makes hydrogen a realistic long-term energy option with little or no pollution, development of new methods for its production and improvement of conventional technology is important. In spite of the fact that, among overall world technologies for hydrogen production today, only 4% is produced by electrolysis, this is the most promising method in the future as a consequence of the high existing water supply. The limitation factor for its use on the large scale is well known-high energy consumption. In this work, methods for increasing efficiency and lowering the energy consumption in the electrolytic hydrogen production are presented. The stability of ionic activators, as an indicator of capital cost, are also shown, as are an analysis of composition, structure and morphology characteristic of cathode, formed in the presence as ionic activators. © 2004 Elsevier B.V. All rights reserved. Keywords: Electrolysis; Hydrogen production; Energy consumption; Cost reduction 1. Introduction Hydrogen production via water electrolysis promises to be of great future importance, especially in countries with cheap electrical energy. Therefore, the development of high-efficiency electrolytic method represents the first step towards the improvement of the hydrogen economy. There were various attempts to improve the electrolytic process with increasing efficiency and lowering carbon emis- sions, and to make electrolysis an acceptable method for hydrogen production, with the idea to adjust all aspects of “hydrogen philosophy” with sustainable development. In our previous work [1], we investigated methods for improvement in the electrolytic method for hydrogen pro- duction from alkalyne solution and Ni-based electrodes, by adding ionic activators into the electrolyte and changing cell geometries. Two types of activators, either tris(ethylene- diamine)Co(III) chloride complex on tris(trimethylenedia- mine)Co(III) chloride complex, gave the best effect in combination with Na–molybdate. It is also known from the literature that the combination of these two d-metals (Co–Mo), from the two branches of Balandin‘s volcano ∗ Corresponding author. Tel.: +381-11-2453-967; fax: +381-11-4447-207. E-mail address: milica@vin.bg.ac.yu (M.P. Marˇ ceta Kaninski). curve [2], creates a remarkable electrocatalytic effect for the hydrogen evolution reaction (HER), most particularly when added in situ during the electrolytic process [3–5]. This is a very simple method for increasing the efficiency of the electrolytic process that does not require high technology. As the result of our previous work [1] activation with these combinations of ionic activators reduces the energy needs per mass unit of hydrogen produced by more than 10% in some cases, compared with those of non-activated electrolytes. The idea of this work was to investigate the activator’s stability in order to estimate the true energy consumption and cost reduction in the electrolytic production of hydro- gen and possible use of this method on a large scale. In addition, our previous results, connected with the reduction of energy consumption, allow an analysis of the compo- sition, structure and morphology characteristic of cathode and an exact determination of the influence of the added ionic activator on the mechanism of electrolytic hydrogen production. 1.1. Theoretical consideration The catalytic activity of various metals for the HER is a periodic function of the atomic number within the three long transition periods of the Periodic Table of Elements [6,7], 0378-7753/$ – see front matter © 2004 Elsevier B.V. All rights reserved. doi:10.1016/j.jpowsour.2004.01.005