%0 Journal Article
%T Fe每N每C electrocatalyst with dense active sites and efficient mass transport for high-performance proton exchange membrane fuel cells
%J -
%D 2019
%R https://doi.org/10.1038/s41929-019-0237-3
%X To achieve the US Department of Energy 2018 target set for platinum-group metal-free catalysts (PGM-free catalysts) in proton exchange membrane fuel cells, the low density of active sites must be overcome. Here, we report a class of concave Fe每N每C single-atom catalysts possessing an enhanced external surface area and mesoporosity that meets the 2018 PGM-free catalyst activity target, and a current density of 0.047ˋAˋcm每2 at 0.88 ViR-free under 1.0ˋbar H2每O2. This performance stems from the high density of active sites, which is realized through exposing inaccessible Fe每N4 moieties (that is, increasing their utilization) and enhancing the mass transport of the catalyst layer. Further, we establish structure每property correlations that provide a route for designing highly efficient PGM-free catalysts for practical application, achieving a power density of 1.18ˋWˋcmˋ2 under 2.5ˋbar H2每O2, and an activity of 129ˋmAˋcmˋ2 at 0.8 ViR-free under 1.0ˋbar H2每air
%U https://www.nature.com/articles/s41929-019-0237-3