fig13

Figure 13. Comparison of ToF-SIMS intensity of NiPACN-3.5 wt% and metal-free PACN: (A) at m/z = 109.94 (⁵⁸NiN₂C₂ weight); (B) at m/z = 111.94 (⁶⁰NiN₂C₂ weight)^[110]. Copyright 2020, Wiley-VCH; ToF-SIMS positive spectrum results of (C) Co Pc and (D) Cu Pc before and after constant potential measurements^[111]. Copyright 2023, The Royal Society of Chemistry; The ToF-SIMS spectra of FeCu-DAC and Fe/Cu-SAC. Ionized fragments of (E) [FeCuN₄O₂]^-, (F) [FeN₄]^-, and (G) [CuN₄]^- are compared for FeCu-DAC and Fe/Cu-SAC^[78]. Copyright 2023, American Chemical Society. ToF-SIMS: Time-of-flight secondary ion mass spectrometry; PACN: DAC: dual-atom catalyst; SAC: single-atom catalyst.