Conformation-modulated three-dimensional electrocatalysts for high-performance fuel cell electrodes
Jong Min Kim, Ahrae Jo, Kyung Ah Lee, Hyeuk Jin Han, Ye Ji Kim, Ho Young Kim, Gyu Rac Lee, Minjoon Kim, Yemin Park, Yun Sik Kang, Juhae Jung, Keun Hwa Chae, Eoyoon Lee, Hyung Chul Ham, Hyunchul Ju, Yeon Sik Jung, Jin Young Kim
Abstract
Unsupported Pt electrocatalysts demonstrate excellent electrochemical stability when used in polymer electrolyte membrane fuel cells; however, their extreme thinness and low porosity result in insufficient surface area and high mass transfer resistance. Here, we introduce three-dimensionally (3D) customized, multiscale Pt nanoarchitectures (PtNAs) composed of dense and narrow (for sufficient active sites) and sparse (for improved mass transfer) nanoscale building blocks. The 3D-multiscale PtNA fabricated by ultrahigh-resolution nanotransfer printing exhibited excellent performance (45% enhanced maximum power density) and high durability (only 5% loss of surface area for 5000 cycles) compared to commercial Pt/C. We also theoretically elucidate the relationship between the 3D structures and cell performance using computational fluid dynamics. We expect that the structure-controlled 3D electrocatalysts will introduce a new pathway to design and fabricate high-performance electrocatalysts for fuel cells, as well as various electrochemical devices that require the precision engineering of reaction surfaces and mass transfer.