Developing highly efficient and low-cost electrocatalysts for the oxygen reduction reaction (ORR) is the key to the fabrication of commercially viable fuel cell devices and metal-air batteries for future energy applications. Here, we report cobalt modified polypyrrole (PPy) nanosheets as a novel non-precious metal electrocatalyst for the ORR. Cobalt modified montmorillonite (Co-MMT) is used as a flat nanoreactor to generate the PPy nanosheets with planar configuration and facilitate the formation of Co-N sites. The planar configuration of PPy benefits the electron transfer and the exposure of the Co-N active sites for the catalysis of ORR. This study opens a new way to rationally design inexpensive and environmental friendly electrocatalysts for the ORR. (C) 2015 Elsevier Ltd. All rights reserved.