Composite materials from transition metal carbides and ionic liquids as electrocatalyst for hydrogen evolution in alkaline media

Abstract Research on the production of high-quality hydrogen is an important step to face the environmental problems caused by using fossil fuels. In this sense, water electrolysis appears as a good option to fulfil this need. However, the application of this technology at low-temperature ranges requires catalysts to carry out the reaction. Nowadays, commercial catalysts in basic media are mainly nickel-based materials, which are rapidly deactivated under operation conditions. This increases the price of H2 production. Therefore, new non-noble electrocatalyst materials are required to improve this feature. Current work describes the preparation and performance towards the hydrogen evolution reaction (HER) of various composite materials generated from powdered transition metal carbides (TMCs) and a pyridinium-based ionic liquid. Differential electrochemical mass spectrometry (DEMS) has been used to obtain an accurate measurement of the activity and to establish the kinetics of HER for the composite materials in NaOH 0.1 M media. The main results show that the ionic liquid acts as an inhibitor or promoter of oxide growth on the surface of the carbide depending on its nature. Because of this effect, there is an increase or decrease of the mean particle size of the material and, therefore, the catalytic performance towards HER is modified. So, it is concluded that the nature of the starting carbide is playing a central role in the interaction with the ionic liquid, changing the catalytic properties of the composite material.