Electrochemical investigation of novel reference electrode Ni/Ni(OH)₂ in comparison with silver and platinum inert quasi-reference electrodes for electrolysis in eutectic molten hydroxide

Abstract

An efficient and green energy carrier hydrogen (H2) generation via water splitting reaction has become a major area of focus to meet the demand of clean and sustainable energy sources. In this research, the splitting steam via eutectic molten hydroxide (NaOH-KOH; 49-51 mol%) electrolysis for hydrogen gas production has been electrochemically investigated at 250-300 o C. Three types of reference electrodes such as a high-temperature mullite membrane Ni/Ni(OH)2, quasi-silver and quasi-platinum types were used. The primary purpose of this electrode investigation was to find a suitable, stable, reproducible and reusable reference electrode in a molten hydroxide electrolyte.Cyclic voltammetry was performed to examine the effect on reaction kinetics and stability to control the working electrode at different scan rate and molten salt temperature. The effect of introducing water to the eutectic molten hydroxide via the Ar gas stream was also investigated.When the potential scan rate was changed from 50 to 150 mV s -1 , the reduction current for the platinum wire working electrode was not changed with newly prepared nickel reference electrode that designates its stability and reproducibility. Furthermore, increasing the operating temperature of molten hydroxides from 250 to 300 o C the reduction potential of the prepared nickel reference electrode is slightly positive shifted about 0.02 V. This suggests that it has good stability with temperature variations. The prepared nickel and Pt reference electrode exhibited stable and reliable cyclic voltammetry results with and without the presence of steam in the eutectic molten hydroxide while Ag reference electrode exposed positive shifts of up to 0.1V in the reduction potential. The designed reference electrode had a more stable and effective performance towards controlling the platinum working electrode as compared to the other quasi-reference electrodes. Consequently, splitting steam via molten hydroxides for hydrogen has shown a promising alternative to current technology for hydrogen production that can be used for thermal and electricity generation.

Platinum Atoms and Nanoparticles Embedded Porous Carbons for Hydrogen Evolution Reaction

“…Since Boddy et al reported the first scientific case on water splitting by using n-type semiconductor TiO 2 as anode material in 1968 [3], many researchers have been devoted to the study of hydrogen production by water splitting [4][5][6][7][8][9]. Conventional hydrogen production methods are mainly based on fossil-fuel technology, such as steam reforming [9], partial oxidation and coal gasification [10,11], which are not sustainable and usually lead to heavily CO 2 emission.…”

Electric discharge drilling with gas-assisted multi-hole slotted tool

“…A high MRR was caused by an increase in discharge current. This is due to the enhancement of the discharge energy in the machining region which reason added evaporation and melting of the work material [22]. Figure 4(a) shows that the MRR improved with an increase in the air pressure discharge reaching its maximum value and then started to decrease at a low discharge current.…”

“…At high duty cycle, large discharge energy and impetuous force were produced which resulted in larger sized carters on the workpiece, as a consequence, the surface finish decreased with a rise in duty cycle [21,29]. At the same time, for high pulse duration, the enlargement of the plasma channel took place in the gap of electrodes, because of which the peak current and magnitude of impulsive force decreased [22]. Thus a formation of shallower carter occurred at the surface of the workpiece, which reduces the surface roughness.…”

“…Researchers have also explored the use of different novel reference electrodes in various processes [22][23]. The finding indicated that novel electrodes have a positive impact on the performance of the process.…”

Influence of the addition of multi‐walled carbon nanotubes on the thermal and mechanical properties of polyamide‐11 before and after aging tests

“…With the rapid technological advancement, there is a need to develop materials with better performances and, thus, the study of composites is of high relevance and stands out for improving the thermal and mechanical properties of polymeric matrices 8–11 . Currently, nanotechnology is a science widely applied in various researches, for example, in the removal of textile dyes and in organic‐based electroactive polymeric materials that play an essential role in the field of science and technology 12–14 .…”