At the Universitat Autònoma de Barcelona, we are producing thin films with potential use in energy generation and storage. These films can act as a catalyst for the hydrogen evolution reaction, i.e. to produce hydrogen gas from water. With the goal to reduce the use of the costly noble metal platinum – the best catalyst so far – we are creating thin films with a porous structure in order to increase the so-called surface-to-volume ratio of the film. The reaction from protons (H+) to hydrogen gas takes place at the surface of the film, so that a larger surface area introduced by the porosity increases the efficiency of the films while at the same time the amount of metal needed is decreased. Additionally, we partially substitute platinum with more abundant elements like nickel.
The films are synthesised in a one-step electrochemical process using metal salts, and a polymer additive which introduces porosity in the order of 10 nm (mesoporosity). The hydrogen evolution reaction is performed in sulfuric acid. Results show that the films have a homogeneously porous architecture and that the production of hydrogen at the surface works stably and is reproducible. In the next steps, the films will be tested for their durability and for application in a fuel cell set-up.