The electrochemical behavior of Th(IV) ion on molybdenum (Mo) electrode was studied by cyclic voltammetry (CV) and square wave voltammetry (SWV) technologies at 773 K in ThF4-LiCl-KCl melt. The reduction of Th(IV) to metal Th at -1.67 V (vs. Ag/AgCl) is a four-electron exchange process, which is quasi-reversible and diffusion-controlled. The diffusion coefficient (D) and activation energy of diffusion process for Th(IV) were determined to be 3.77 x 10 (5) cm(2) s (1) and 59.2 kJ mol (1). The pulse potential electrolysis of ThF4-LiCl-KCl melt revealed that 86.8% of Th(IV) can be separated from the melt based on the inductively coupled plasma atomic emission spectrometer (ICP-AES) results. (C) 2016 Elsevier Ltd. All rights reserved.