The non-catalytic and catalytic oxidations of CH4 over Mo-V-Cr-Bi-Si oxide catalysts were investigated in a tubular reactor and the catalysts were characterized by XRD, XPS and TPR, Contents of Bi in the catalysts influenced the combination of Mo-V-Bi-O species and, consequently, influenced the TPR reduction temperature of the catalysts. The catalysts exhibited more selective production of methanol when the TPR reduction peaks shifted to lower temperature. (C) 2002 Elsevier Science Ltd. All rights reserved.