For catalytic combustion of chlorobenzene (CB), a series of cobalt-based double perovskites La2BCoO6 (BCu, Fe, Ni, Al) were synthesized by sol-gel method. These double perovskites were controllably etched by nitric acid to remove part of surface A-site and improve their catalytic activity for catalytic combustion of CB, toluene and benzene. Crystalline structure, micromorphology, surface composition, redox properties, oxidation state of the catalysts were investigated in detail by various methods. Concentration of nitric acid and the etching time were used to tune the surficial active sites of B and B′ (Cu, Co) whilst maintaining the structure. Among these double perovskites, La2CuCoO6 had the strongest oxidation ability and acidity and showed the best catalytic performance. Temperature for 90% conversion of CB (T90) on La2CuCoO6 etched by 5% nitric acid was 260 °C lower than that of as-prepared La2CuCoO6. T90 for combustion of toluene and benzene is only 240 and 290 °C, respectively. The nitric acid etching also resulted in a change in the surface charge of the Cu, Co sites, provided an oxidation cycle of Cu2++Co2+↔Cu++Co3+, which facilitated the production of surficial active oxygen, accelerated the oxygen mobility and enhanced the catalytic performance. La2CuCoO6 etched by 5% nitric acid showed good catalytic stability over 100 h testing. This work shows a novel, facile approach to prepare efficient and stable catalysts for chloride containing VOCs catalytic combustion.