“…Figure shows the Ni 2p 3/2 XPS patterns of Ni/AC and bimetallic Cu-Ni/AC. As shown in Figure , Ni 2p 3/2 XPS spectra can be fitted into three components; the peaks around 853.1, 854.6, and 856.6 eV are attributed to Ni metal, Ni oxide (NiO), and Ni hydroxides (Ni(OH) 2 and NiOOH), respectively. , Additionally, the peak at 861.7 eV is ascribed to the shake-up satellite, which is due to the multielectron excitation of high-valence nickel. , Noticeably, it can be observed from Figure b,c that the peak intensity of Ni metal increases with the introduction of a small amount of Cu (0.5 and 1 wt %), indicating that Cu can effectively promote NiO reduction and facilitate metal Ni exposure. ,, However, as can be seen in Figure d–g, the intensity of Ni 0+ decreases with the introduction of excessive Cu, and the reason may be that excessive Cu can promote the formation of larger metal oxide nanoparticles and NiO–CuO eutectic so as to inhibit NiO reduction . These results are in agreement with the H 2 -TPR results in Figure .…”