(color online) STEM-HAADF images and spectra of the Co-^SMoS₂ catalyst. (a) The magnified STEM-HAADF image of fresh Co-^SMoS₂. (b) The corresponding HAADF intensity line scanning in (a). (c) The simultaneous EELS acquired along the line in (a). (d) The HAADF image of Co sitting on the Mo-atop site (marked in white arrow) in fresh catalysts. (e) HAADF image of Co-substituted S site (marked in white arrow) in used catalysts. (f) The HAADF image of Co occupying in the hollow site (marked with white arrow) in used catalysts. ((g)–(i)) The corresponding simulated HAADF images, respectively.^[23]