Novos Avanços na Eletrocatálise de Água: Uma Revisão sobre a Forma mais Sustentável de Produzir Hidrogênio

Resumo

Hydrogen represents the greatest opportunity for green fuel. When burned, it produces water as a product
and has an energy density higher than gasoline. However, hydrogen production still faces challenges,
the main one being the production of carbon-free hydrogen. Therefore, this work aims to present the
most modern alternatives for hydrogen production, considering various aspects. Among them, the use of
seawater and the development of MnO_x-based electrodes that are resistant to chlorine. The development
of advanced electrode synthesis techniques enabled this achievement, focusing on carbon-based metalorganic frameworks containing isolated metal atoms and nanoparticulate aggregates. Carbon nanofibers
with confined cobalt nanoparticles, and heterostructures, such as three-dimensional mesoporous
graphene structures and nitrogen-doped MoS₂, which enable reduced metal usage are examples of such
nanostructured materials. Additionally, this work seeks to systematically introduce the state-of-art, as
established in the scientific community regarding the reaction mechanisms for the water oxidation and
reduction steps, presenting the Volmer’s reactions as the kinetic limiting step of the reduction process
and oxygen evolution as the limiting step of the overall process.