Fig. 2
From: Highly selective oxygen reduction to hydrogen peroxide on transition metal single atom coordination
Atom probe tomography of Fe-CNT catalyst. a The schematic of the nanofabrication procedure of APT sample tips. b The cross-section SEM image of a catalyst sandwich after FIB cutting. c SEM image of the final APT specimen tip anchored on a Si microtip after sharpening. d Reconstructed APT data for a region containing Fe-CNT, with (e) a 2D contour plot of C atomic concentration and f the corresponding reconstruction for a region of 40 × 40 × 80 nm surrounding a CNT. g Side and top view of CNT planes, where single Fe atoms may have direct coordination with both C and O. The vacant space is mainly due to the low detection efficiency of atoms. Atom labels, Au in yellow, Fe in green, C in gray, and O in red in d–g; Scale bars, 500 nm in b, 200 nm in c, 20 nm in d–f, and 2 nm in g
