We present a study of ultraviolet photoemission spectroscopy (UPS) and constant-initial-state spectroscopy (CIS) of lithium nickel oxide using synchrotron radiation. The top valence-band structure of Li0.1Ni1.9O2 and LiNiO2 has been applied to the investigation of selectivity for oxidative coupling of methane. It is suggested that lattice oxygen species are separable into two bands, and the proportion of the two O(2)p and Ni3d states was related to the function of the selective oxidation. (c) 2008 Elsevier B.V. All rights reserved.