Highly Efficient Alkaline Water Electrolysis Using Alkanolamine-Functionalized Zirconia-Blended Separators

Abstract

Alkaline water electrolysis is one of the most promising technologies for green hydrogen production. Here, we synthesized a series of alkanolamine-modified zirconia particles by a one-pot method to construct zirconia-based composite membranes for alkaline water electrolysis. Among these membranes, the diethanolamine (DEA)-functionalized zirconia separator exhibits superior hydrophilicity with a low water contact angle of 44°and low area resistance of 0.12 Ω•cm 2 , which were 47 and 60%, respectively, less than that of the commercial Zirfon PERL UTP 500 separator. Conceivably, the DEA-functionalized zirconia separator presents high electrochemical performance with a current density of 1114 mA cm −2 at 2.0 V with Raney Ni as the cathode catalyst and CoMnO@CoFe layered double hydroxide (LDH) as the anode catalyst at 80 °C, closing the gap with proton exchange membrane electrolysis. In addition, the DEA-modified separator exhibits high stability for over 150 h at a high current density of 500 mA cm −2 and stable cell voltages in 30 wt % KOH at 80 °C.

Hydrophilic Chitosan-Doped Composite Diaphragm Reducing Gas Permeation for Alkaline Water Electrolysis Producing Hydrogen

“…The alkaline uptake reflected the effect of the electrolyte on the hydrophilicity of the composite diaphragm; the greater the alkaline uptake, the greater the pore structure of the membrane and the superior the hydrophilicity. 34 The alkali uptake and porosity of the diaphragm followed trends similar to each other, with the greatest alkaline uptake (56.48%) being for CS 3 Z 12 . Compared to Z 15 and commercial porous diaphragm Zirfon PERL, the diaphragm CS 3 Z 12 offered superior hydrophilic properties.…”

Bubble Management for Electrolytic Water Splitting by Surface Engineering: A Review

“…Surface functionalization aims to alter the surface energy by introducing hydrophilic groups onto the electrode surface (as shown in Figure a,b), thus resulting in the changes in wettability and bubble evolution. − Compared with morphology control and hydrophilic coatings, surface functionalization modifies the new physical and chemical properties of electrodes by functional groups, which is a target-oriented strategy. ,,, …”

“…Copyright 2021 John Wiley and Sons Ltd. (b) Preparation of alkanolamine-functionalized ZrO 2 . Reproduced with permission from ref . Copyright 2023 American Chemical Society.…”

“…Until now, more fabrication processing and functional strategies appeared such as hydrothermal codeposition, the ionic layer adsorption method, the vapor-assisted treatment approach, and electrochemical deposition . For instance, Dastafkan et al simply synthesized a vanadate-modified iron–nickel catalyst.…”

“…109−113 Compared with morphology control and hydrophilic coatings, surface functionalization modifies the new physical and chemical properties of electrodes by functional groups, which is a target-oriented strategy. 101,103,104,112 Niu et al 114 anodized the screen-printed carbon electrodes (SPCE) by chronoamperometry, and negatively charged oxygen-containing functional groups were introduced. The functional groups increased the hydrophilicity and decreased the bubble coverage on the electrode surface, resulting in the promoted activity of anodized SPCEs with a lower overpotential η bub .…”