Electrolysis of ammonia for hydrogen production catalyzed by Pt and Pt-Ir deposited on nickel foam

Abstract

Electrolysis of ammonia in alkaline electrolyte solution was applied for the production of hydrogen. Both Pt-loaded Ni foam and Pt-Ir loaded Ni foam electrodes were prepared by electrodeposition and served as anode and cathode in ammonia electrolytic cell, respectively. The electrochemical behaviors of ammonia in KOH solution were individually investigated via cyclic voltammetry on three electrodes, i.e. bare Ni foam electrode, Pt-loaded Ni foam electrode and Pt-Ir loaded Ni foam electrode. The morphology and composition of the prepared Ni foam electrode were analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Effects of the concentration of electrolyte solution and temperature of electrolytic cell on the electrolysis reaction were examined in order to enhance the efficiency of ammonia electrolysis. The competition of ammonia electrolysis and water electrolysis in the same alkaline solution was firstly proposed to explain the changes of cell voltage with the electrolysis proceeding. At varying current densities, different cell voltages could be obtained from galvanostatic curves. The low cell voltage of 0.58 V, which is less than the practical electrolysis voltage of water (1.6 V), can be obtained at a current density of 2.5 mA/cm 2 . Based on some experimental parameters, such as the applied current, the resulting cell voltage and output of hydrogen gas, the power consumption per gram of H 2 produced can be estimated.

High Mass and Specific Activity for Ammonia Electro‐oxidation through Optimization of Dispersion Degree and Particle Size of Pt‐Ir Nanoparticles over N‐Doped Reductive Graphene Oxide

“…Recently, a considerable effort has been devoted to developing high‐performance Pt‐based electrocatalysts that are able to effectively enhance ammonia electro‐oxidation kinetics, and simultaneously, significantly decreasing Pt loading through applying Pt‐based bimetallic nanoparticles, constructing special structure or morphology, and dispersing nanoparticles on the appropriate substrate ,,. In general, alloying Pt with other metals causes a series of geometric and electronic effects resulting in the enhancement of electrocatalytic activity of Pt .…”

Alkaline Ammonia Electrolysis on Electrodeposited Platinum for Controllable Hydrogen Production

“…Sufficient ammonia is adsorbed on the catalyst surface at the beginning of electrolysis,b ut as electrolysis proceeds, the www.chemsuschem.org adsorbed ammonia is consumed to satisfy the appliedc urrent, thus creatingascarcityo fa dsorbed ammonia, which finally leads to the reaction characterizedb yt he evolution of oxygen. [1] The flow rate of gas production emitted from the cathode at variousc onstant-current conditions was measured using ab ubble flow meter;t he gas was qualitativelya nalyzed by gas chromatography (GC, Figure 7b). Through aq ualitativea nalysis of gas production,i tw as demonstrated that only hydrogen is emitted at the cathode from ammonia electrolysis.…”

“…[1] Hydrogen attracts increasing interesta sa na lternative energy source (theoretical energy density of hydrogen = 141 kJ g À1 ). [2,3] Despite the numerous advantages of hydrogen as an alternative energy source,e fficient hydrogen production from water,h igh pressure storage, andt ransportation remain very difficult.…”

“…Economic and political issues along with environmental problems recently arose owing to the exhaustion of conventional fuels and the emission of carbon dioxide from ad ramatically increasing consumption of fossil energy. [1] Hydrogen attracts increasing interesta sa na lternative energy source (theoretical energy density of hydrogen = 141 kJ g À1 ). [2,3] Despite the numerous advantages of hydrogen as an alternative energy source,e fficient hydrogen production from water,h igh pressure storage, andt ransportation remain very difficult.…”

Nitrogen-doped porous carbons from bipyridine-based metal-organic frameworks: Electrocatalysis for oxygen reduction reaction and Pt-catalyst support for methanol electrooxidation

“…6a and b showed the SEM images of Pt/NPC800 at different magnifications. It was observable that Pt slice-like aggregates [56] had successfully loaded on NPC800 through electrodeposition and the average size of Pt particles was about 1 lm. It was worthy of noting that Pt particles mainly deposited on NPC800 other than glassy carbon electrode substrate, which was possibly due to the stabilization of Pt particles by NPCs.…”