The design of catalytic oxidation processes with high efficiency has attracted considerable attention for a long while in environmental catalysis. In this work, a novel oxidation system, CFs-CoPc/PMS, was developed by coupling cellulosic fibers-bonded cobalt phthalocyanine (CFs-CoPc) with peroxymonosulfate (PMS). CFs-CoPc/PMS system could effectively decolorize azo dyes such as Acid Red 1 (AR1) with almost 100% decolorization efficiency in 35 min, suggesting that the CFs-CoPc/PMS system was a highly efficient oxidation process. In addition, bicarbonate ion (HCO3-) was further introduced to CFs-CoPc/PMS to construct a combined system, CFs-CoPc/PMS/HCO3-. Remarkably, this system turned the negative effect of HCO3- observed in most reported Co/PMS systems into a positive one, which enhanced the AR1 decolorization with over 2-fold increase of the rate constant. The main factor responsible for the enhancement was high-valent cobalt-oxo intermediates (PcCoIV=O), which was presumably generated via the heterolytic cleavage of the PMS OO bond by CoPc-HCO3- complex. It is noteworthy that high-valent cobalt-oxo intermediates as the major active species is different from most reported mechanisms in Co/PMS systems, in which hydroxyl and sulfate radicals are recognized as the dominant active species. This study paves an avenue for developing highly efficient catalytic oxidation technology for wastewater remediation. (C) 2015 Elsevier B.V. All rights reserved.