One-pot synthesis via confined mesopore using a citrate-based metal precursor was applied to obtain a perovskite-type metal oxide with a high surface area for total oxidation of toluene. The method produced LaCoO3 with a higher surface area (147 m(2)/g) and smaller crystallite size (8 nm) than conventional methods, such as the co-precipitation and citrate sol-gel method. The citrate-based metal precursors were inserted in the framework of mesopore and the crystallite size of LaCoO3 converted from these precursors could be adjusted with the confinement effect by mesoporous structure formed with LaCoO3 simultaneously. The catalytic activity for the total oxidation of toluene over LaCoO3 showed a good correlation with the high surface area, which was confirmed by characterization of the chemical states of LaCoO3. (C) 2015 Elsevier B.V. All rights reserved.