Electrochemically Fabricated NiW on a Cu Nanowire as a Highly Porous Non-Precious-Metal Cathode Catalyst for a Proton Exchange Membrane Water Electrolyzer

Abstract

A hierarchical Ni x W100–x /Cu nanowire (NW) catalyst for the acidic hydrogen evolution reaction was electrochemically fabricated on carbon paper (CP) for practical applications of a proton exchange membrane water electrolyzer (PEMWE). The Ni and W contents in the catalysts were controlled by adjusting the concentration of Ni and W precursors during electrodeposition. The as-prepared catalyst had an amorphous structure due to the addition of W. The activities of Ni x W100–x /Cu NW/CP catalysts were evaluated for hydrogen evolution. The Ni96W4/Cu NW/CP catalyst had the highest intrinsic activity among the catalysts with an overpotential of 56 mV at −10 mA cm–2, whereas those of Ni100/Cu NW/CP and Ni96W4/Cu/CP were 177 and 77 mV, respectively. The performance improvement was attributed to the amorphous structure of NiW and the use of a large surface area of Cu NW as a porous sublayer. Finally, Ni96W4/Cu NW/CP was implemented as the cathode of a PEMWE which offered a performance that was ∼80% of that of a Pt-cathode-embedded electrolyzer and 320% of that of a non-Pt-cathode-embedded electrolyzer at 2.0 Vcell, as reported in the recent literature.

Christmas‐Tree‐Shaped Palladium Nanostructures Decorated on Glassy Carbon Electrode for Ascorbic Acid Oxidation in Alkaline Condition

“…Therefore, welldefined nanostructure fabrication has garnered much attention recently. [4][5][6][7][8] Although different solution-based metal nanoparticle syntheses and their assemblies have been developed successfully and used in diverse applications, the fabrication process requires multiple steps and/or linker molecules. [9] These linker molecules and capping agents for the preparation of nanostructure could potentially affect the surface morphology and electroanalytical activities.…”

“…The fabrication process can control the shapes and sizes of metal nanostructures, which provide unique physical and chemical properties. Therefore, well‐defined nanostructure fabrication has garnered much attention recently [4–8] . Although different solution‐based metal nanoparticle syntheses and their assemblies have been developed successfully and used in diverse applications, the fabrication process requires multiple steps and/or linker molecules [9] .…”

Facile electrochemical preparation of nonprecious Co‐Cu alloy catalysts for hydrogen production in proton exchange membrane water electrolysis

“…For hydrogen production in PEMWEs, platinum group metals (PGMs) have been commonly used as the cathode catalyst owing to their high corrosion resistance and superior catalytic activity . However, to reduce the cost of catalysts, alloy or compound catalysts based on non‐noble metals (Ni, Co, Mo, W, Cu, etc) have been extensively studied as potential substitutes . Among non‐noble‐metal‐based catalysts, Co‐based catalysts, which are well known to have relatively high catalytic activities for the hydrogen evolution reaction (HER), are expected to replace PGM‐based catalysts .…”

“…[22][23][24][25][26][27][28][29] However, to reduce the cost of catalysts, alloy or compound catalysts based on non-noble metals (Ni, Co, Mo, W, Cu, etc) have been extensively studied as potential substitutes. [30][31][32][33][34][35][36][37] Among non-noble-metal-based catalysts, Co-based catalysts, which are well known to have relatively high catalytic activities for the hydrogen evolution reaction (HER), are expected to replace PGM-based catalysts. 32,38,39 However, the catalytic activity of Co is significantly lower than that of Pt; furthermore, Co could dissolve in acidic solution because its standard reduction potential is −0.277 V vs the normal hydrogen electrode (NHE), resulting in poor durability.…”

Advanced Electrocatalysis for Energy and Environmental Sustainability via Water and Nitrogen Reactions

“…For the water cycle, the transformation of renewable electricity into chemical energy in the form of covalent bonds of H 2 and O 2 via water electrolyzers largely depends on the OER at the anode. [ 24–26 ] The ORR is crucial for the subsequent electricity generation and H 2 O production via PEMFCs. [ 10,27,28 ] For the nitrogen cycle, NRR and AOR catalytic processes relate to the breaking and forming of NN bonds, [ 29 ] respectively, ideal for electrochemical ammonia (NH 3 ) synthesis from N 2 and DAFCs via utilizing NH 3 as a carbon‐free fuel.…”