Ref.: MCoMge32-008
Apresentador: Haroldo Cavalcanti Pinto
Autores (Instituição): Pinto, H.C.(Escola de Engenharia de São Carlos da Universidade de São Paulo); Moreira Delfino, G.(Escola de Engenharia de São Carlos da Universidade de São Paulo); Mehmood, R.(Escola de Engenharia de São Carlos da Universidade de São Paulo); Rêgo, G.C.(Escola de Engenharia de São Carlos - Universidade de São Paulo); de Oliveira Santiago Santos, G.(Instituto de Química de São Carlos da Universidade de São Paulo); Santa Rosa, W.(Instituto de Física de São Carlos da Universidade de São Paulo); Moreto, J.A.(Universidade de São Paulo); Gonçalves, R.V.(São Carlos Institute of Physics, University of São Paulo.); de Vasconcelos Lanza, M.(Instituto de Química de São Carlos da Universidade de São Paulo);
Resumo:
Proton exchange membrane (PEM) electrolyzer is exceptional among the other electrolyzers in terms of higher purity of hydrogen and current densities [1]. However, noble metal as a catalyst in membrane electrolyte assembly (MEA) is one of the key hurdles to make it commercialize on the larger scale. Transitional metals are considered to be one of the key catalysts for the production of hydrogen due to its unique electronic structure and high earth abundance [2]. Low cost, high abundance and good catalytic activity makes nickel nanoparticles (Ni-NPs) a promising bifunctional catalyst in PEM electrolyzer for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) [3]. In this work, Ni-NPs catalysts were developed by radio frequency (RF) sputtering and chemical synthesis at various deposited thickness directly on carbon fiber enriched with nitrogen (g-CN) as cathode for the water electrolysis. X-ray photoelectron spectroscopy (XPS), x-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to gain insight into the morphological and structural features of the prepared electrodes. Three electrode systems and cyclic voltammetry (CV) were employed to understand the electrochemical activities of the HER and OER performances. Our findings indicated that sputtering deposited Ni-NPs showed enhanced catalytic activity for HER and OER by means of controlled deposition thickness and synergistic effects with the nitrogen enriched carbon and stainless steel meshes. In addition, optimum thickness of Ni-NPs showed better catalytic activity as compared to the commercial Pt/C. Therefore, presented Ni-NPs/g-CN, Ni-NPs/Ti mesh as an efficient and inexpensive bifunctional catalyst for the PEM electrolyzer.