Exploring advanced electrocatalysts to accelerate the sluggish methanol oxidation reaction (MOR) in the anode of direct methanol fuel cells is a promising route to alleviate the current challenges of fossil fuel exhaustion and environmental pollution. Herein, we develop capping-free PdCo alloys with a coral-like structure and use them as potential electrocatalysts to promote the MOR in alkaline media. A facile microwave-assisted wet chemical approach was established to prepare the unique PdCo architectures, in which no capping agent was employed. Through regulating the precursor ([PdCl4](2-) and Co2+) proportion, the ratio of bimetals could be expediently tailored. HRTEM, SAED, XRD and XPS verified the formation of PdCo alloys with different Co abundances on surface. It was found that, together with morphology and crystallinity, the electrocatalytic activities of PdCo materials toward methanol oxidation were highly dependent on their compositions. Among synthesized PdCo structures, the best Pd56Co44 with a moderate Co enrichment on the alloy surface exhibited a mass activity dramatically 11.4 times higher than the pure Pd counterpart. This impressive activity of Pd56Co44 synergistically originated from the bifunctional effects and the electronic interactions between Pd and Co. In addition, the good performance durability of bimetallic PdCo was also demonstrated. (C) 2017 The Electrochemical Society. All rights reserved.