Cation exchange membranes (CEMs) have been prepared from sulfonated poly(phenylene oxide) (SPPO) by electrospinning and hot-press treatment. Effect of various parameters, such as concentration, voltage and tip to collector distance (TCD) as well as the hot-press treatment conditions on properties of membrane has been fully investigated. When being applied in diffusion dialysis (DD) for alkali recovery from Na2WO4/NaOH solution, the membrane exhibits higher hydroxide permeability (U-OH, 0.00971 m/h) and separation factor (S, 36.09) than the solution casting SPED membrane (CSPPO), of which U-OH is only 0.00605 m/h and S is 21.8. Compared with previously reported DD membranes with U-OH in the range of 0.0014-0.0022 m/h, Hot-pressed Electrospun SPED (H-ESPPO) shows approx. 4 times higher in U-OH, underling its superior performance in DD application. (C) 2014 Elsevier B.V. All rights reserved.