Carbon black (CB), which has been widely used as a catalyst support, has been treated by various activation processes in order to increase the surface area. High-surface-area CB has a high pore volume in the primary particles. The degree of ionomer impregnation in the nanosized pores is able to be evaluated by the hysteresis volume, which is calculated from N2-adsorption analysis. We investigated the effect of distributions of both Pt and ionomer on the surface of CB support nanopores on the cell performance and durability of cathode catalyst layers with catalysts using CB with various nanopore volumes for polymer electrolyte fuel cells. The optimum ionomer content is affected by the nanopore volume, and the excess ionomer was found to block the entrances of the nanopores. For maximizing the cell performance and durability, we found that a high-surface-area CB was beneficial for achieving decreased Pt particle size, and the ionomer content was optimized to prevent the blocking of the nanopores. Improvement of the transport of oxygen and protons to Pt in the nanopores and increase in the interparticle distance led to both increase in the electrochemical surface area and suppression of Ostwald ripening and coarsening.

Achieving high performance and durability at low Pt loads is an important challenge for polymer electrolyte fuel cells (PEFCs). We investigated the effect of catalyst Pt loading percentage (wt % Pt) on the performance and durability of an ultrahigh surface area carbon black (CB) with a large nanopore volume using morphological observations, nitrogen adsorption, and electrochemical performance measurements. The ratio of the surface areas of Pt on the interior and exterior surfaces of the CB affects the penetration of the ionomer into the nanosized pores. When the exterior Pt surface area is larger than that of the interior, the oxygen diffusion resistance in the ionomer increases and the performance deteriorates due to the thick covering of the ionomer on the exterior Pt. Based on durability testing that combines startup, shutdown, and galvanostatic load cycling, the main deterioration factors are dependent upon the Pt interparticle distance and the thickness of the catalyst layer, which vary with the wt % Pt. The advanced characterization and optimization of the various wt % Pt on an ultrahigh surface area CB, combined with the extensive performance and durability testing, have provided an unprecedented understanding of the reaction sites, mass transport characteristics, and stability, which are crucial for their practical application in PEFCs.

In 1552, Luis de Aimeida, a Portuguese physician, brought Western medicine and surgery to Japan. He was also a missioner and merchant, and with his wealth, he built orphanages and hospitals practicing surgery in Nagasaki, Japan. Following this, medicine was taught at small schools in Japan using textbooks brought from the Western world. According to the existing record, Seishu Hanaoka resected breast cancer under general anesthesia on 14 November 1804 with extract of Datura metel. By 1875, a medical licensing system was established in Japan. Women, however were not allowed to apply for the licensing examination until 1884. The very first female surgeon in Japanese history was Ine Kusumoto, the daughter of Kusumoto Taki and Philipp Franz Balthasar von Siebold. Von Siebold was a German physician, who lived in Japan from 1823 to 1828, during the era of national isolation. Dr. Kusumoto studied medicine and became the very first female gynecologist in Japan. However, she was never permitted to take the licensing examination. The first Japanese woman officially certified in surgery was Ginko Ogino, who started her life in medicine after she contracted gonorrhea from her husband.