Metal–organic framework–derived Ni@C and NiO@C as anode catalysts for urea fuel cells

• Published in: Scientific reports Vol. 10; no. 1; p. 278
• Main Authors: Tran, Thao Quynh Ngan, Park, Bang Ju, Yun, Woo Hyun, Duong, Tien Nhac, Yoon, Hyon Hee
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 14.01.2020; Nature Publishing Group
• Subjects: 639/301/299/886; 639/301/299/893; 639/301/299/921; Catalysts; Electrochemistry; Fuel cells; Fuel technology; Humanities and Social Sciences; multidisciplinary; Oxidants; Oxidation; Oxidizing agents; Science; Science (multidisciplinary); Urea
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-019-57139-7

Highly porous self-assembled nanostructured Ni@C and NiO@C were synthesized via calcination of a Ni-based metal–organic framework. The morphology, structure, and composition of as synthesized Ni@C and NiO@C were characterized by SEM, FIB-SEM, TEM, and XRD. The electro-catalytic activity of the Ni@C and NiO@C catalysts towards urea oxidation was investigated using cyclic voltammetry. It was found that the Ni@C had a higher residual carbon content and a higher specific surface area than NiO@C, thus exhibiting an enhanced electrochemical performance for urea oxidation. A direct urea fuel cell with Ni@C as an anode catalyst featured an excellent maximum power density of 13.8 mW cm −2 with 0.33 M urea solution in 1 M KOH as fuel and humidified air as oxidant at 50 °C, additionally showing excellent stability during continuous 20-h operation. Thus, this work showed that the highly porous carbon-supported Ni catalysts derived from Ni-based metal–organic framework can be used for urea oxidation and as an efficient anode material for urea fuel cells.