This work is devoted to preparation of a hybrid material based on Nafion (R) 212 membrane doped with nanoparticles of silica and cesium acid salt of phosphotungstic heteropolyacid. The benefits of this material are concerned with its increased conductivity at low humidity. Conductivity and properties of the membranes were studied as a function of relative humidity under the FC operating regime at room temperature. As compared with the commercial Nafion (R) 212 membrane, the MEA based on this material shows a lower power density at 100% relative humidity of the supplied gases (hydrogen, air). As the relative humidity decreases, power density of the cell based on hybrid membrane increases and overruns the performance of the commercial Nafion (R) 212 membrane at 100% RH. Explanation of the observed phenomena is proposed. (C) 2015 Elsevier B.V. All rights reserved.