Development of Mn-Mo-X-Y-Z-O based electrocatalytic materials for making hydrogen fuel from saline water

Abstract

The efficacy of W, Sn, and Sb in Mn-Mo-O-based electrocatalysts explore their catalytic properties of oxygen evolution effectiveness, stability, and durability for hydrogen-energy production from saline water electrolysis. The composition, phase, and surface morphology of the electrodeposited Mn-Mo-X-Y-Z-O (X = W; Y = Sn; Z = Sb) electrocatalysts on the Ir-sn-Sb-O/Ti (TMO) electrode were investigated using X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and confocal scanning laser microscopy (CSLM) techniques. The catalytic properties of the materials were studied using iodometrically and galvanostatic polarization methods in saline solution with 3 % NaCl in acidic (pH 1) conditions at room temperature (25 °C). Three sets of nano-phase Mn-Mo-X-Y-Z-O electrocatalysts are fabricated first time, which play significant roles in the production of sufficient amounts of hydrogen from saline water electrolysis. The fabricated electrocatalysts show nearly 100 % (i.e., 99.6–99.8 %) oxygen evolution efficiency (OEE) after the electrolysis of aqueous 3 % NaCl solution (pH 1; 25 °C) at 1000 A.m−2 current density (CD) for more than five months. The W, Sn, and Sb additions show the beneficial effects on the Mn-Mo-O-based catalysts to maintain high electron-conducting power and the OEE activities for a long time.