Pd–Co-Based Electrodes for Hydrogen Production by Water Splitting in Acidic Media (original) (raw)
Related papers
Platinum–rare earth electrodes for hydrogen evolution in alkaline water electrolysis
International Journal of Hydrogen Energy, 2013
In the new "Hydrogen Economy" concept, water electrolysis is considered one of the most promising technologies for hydrogen production. Novel electrocatalytic materials for the hydrogen electrode are being actively investigated to improve the energy efficiency of current electrolysers. Platinum (Pt) alloys are known to possess good catalytic activities towards the hydrogen evolution reaction (HER). However, virtually nothing is known about the effects of rare earth (RE) elements on the electrocatalytic behaviour of Pt towards the HER. In this study, the hydrogen discharge is evaluated in three different PteRE intermetallic alloy electrodes, namely PteCe, PteSm and PteHo, all having equiatomic composition. The electrodes are tested in 8 M KOH aqueous electrolytes at temperatures ranging from 25 C to 85 C. Measurements of the HER by linear scan voltammetry allow the determination of several kinetic parameters, namely the Tafel coefficients, charge-transfer coefficients, and exchange current densities. Activation energies of 46, 59, 39, and 60 kJ mol À1 are calculated for Pt, PteCe, PteSm and PteHo electrodes, respectively. Results show that the addition of REs improves the activity of the Pt electrocatalyst. Studies are in progress to correlate the microstructure of the studied alloys with their performance towards the HER.
Bangladesh Journal of Scientific and Industrial Research, 2008
Redox behaviors and hydrogen evolution efficiencies of Pd and Mo deposited Pd electrodes have been investigated in 30wt.% KOH electrolyte by cyclic voltammetry. Cyclic voltammograms of Pd electrode in between the potential range - 1.05 V to + 0.75 V showed two couples of redox peaks for the transformations of Pd(0) ←→ Pd(OH)2 and Pd(OH)2 ←→ PdOOH, an anodic peak for the desorption of diffusional hydrogen (dH) and hydrogen and oxygen evolutions at the terminal potential regions. Hydrogen evolution efficiency found decreased with time and then reached to a stable condition after 35 minutes. In presence of deposited Mo, the electrode stable condition appeared after 10 minutes only. Pd found predominates over deposited Mo. Both the Pd(0) ←Pd(OH)2 and Mo(0) ← Mo(OH)2 transformations appeared at the same potential value. Mo stopped the movement of hydrogen adsorption and absorption region of Pd electrode towards negative potential direction. It increased the hydrogen evolution efficiency ...
2011
This work is concerned with the preparation and the characterization of nano-structured composite electrocatalytic material for hydrogen evolution based on Co as a hyper d-metallic phase and anatase (TiO 2) as a hypo d-phase, both deposited on a carbon substrate. The main goal is to replace the Pt as an electrocatalytic material, partially or completely. Two types of support material were used: Vulcan XC-72 and multiwalled carbon nanotubes (MWCNTs). Also two non-platinum metals were used as a hyper d-metallic phase: Ni and Co. The best performances were shown by the Co electrocatalyst, deposited on activated MWCNTs. This one approaches and even slightly exceeds the catalytic activity of the traditional Pt electrocatalyst, deposited on Vulcan XC-72. To improve the disadvantages of this electrocatalyst (instability in acid media and passivation in alkaline media) a precious metal (Pt or Ru) was added into the metallic phase. Only 20 % of the precious metal in the metallic phase consid...
Pd-Au Electrocatalysts for Hydrogen Evolution Reaction at Neutral pH
International Journal of Electrochemistry, 2014
Pd-Au codeposits with different ratio of both metals were electrodeposited on carbon felt, characterized by scanning electron microscopy, and investigated as electrocatalysts towards hydrogen evolution reaction in neutral phosphate buffer solution. The quantities of the produced hydrogen gas with different electrocatalysts, estimated from data obtained by chronoamperometry, were confirmed by mass spectrometry analysis. The highest hydrogen evolution rate was achieved with the electrocatalysts, produced from electrolyte with equal Pd and Au content.
Metal alloys have become ubiquitous choice as catalysts for electrochemical hydrogen evolution in alkaline media. However, scarce and expensive Pt remains the key electrocatalyst in acidic electrolytes making the search for earth-abundant and cheaper alternatives appealing. Herein, we present a facile and efficient synthetic route towards polycrystalline Co3Mo and Co6Mo7 metal alloys that achieve competitively low overpotentials of 115 mV and 160 mV at 10 mA cm–2 in 0.5 M H2SO4. Both alloys outperform Co and Mo metals which showed significantly higher overpotentials and lower current densities when tested under identical conditions. However, the low overpotential in Co3Mo comes at the price of stability. It rapidly becomes inactive when tested under applied potential bias. On the other hand, Co7Mo6 retains the current density over time without the evidence of current decay. The findings demonstrate that even in free-standing form and without nanostructuring polycrystalline bimetalli...
ACS Applied Nano Materials, 2023
A methodologyto preparea stable,PtPdalloy-basedelectrodefor the hydrogenevolutionreaction(HER)isreported.The Pt/Pdmoleratiowas 3.62.Thiselectrodeusesa stainlesssteel(SS)plateas the conductingsubstrate,whichhappensto havehighlyinterconnectedmicrotrencheson the surface.The area coveredby the microtrenchescorrespondedto only28%of thetotalsurfacearea of the SS plate.An amorphousultrathin(<50nm)inorganictitanosilicabinderwas selectivelycoatedonlyontotheinteriorsof the microtrenches,and 2−6nm-sizedPtPdalloynanoparticleswerefinelydispersedinto the amorphouslayer.Thus,thisHERelectroderepresentsthe first exampleto showthat onlya minorportion(28%)of the conductingsubstratewas intentionallymadeto be active.Furthermore,the amountsof Pt and Pd wereverysmall,beingonly2.06and 0.31μg cm−2, or 10.6and 2.9 nmol,respectively,of the wholesubstrate.Despitethatonly28%of the wholesurfacewas coveredby the activesitesand the loadedamountsof Pt and Pd per 1 cm2wereverysmall,the measuredHERoverpotentialsweremuchlowerthanthoseof the reportedPt-basedHERelectrodes,including20%Pt supportedon glassycarbon(Pt/C),in the currentdensityregionbetween0.1 and 1 Acm−2, regardlessof the pH of the electrolytesolution.Loadingof verysmallamountsof Pt (0.5−2.09μg cm−2) on HERelectrodeshas alsobeendemonstratedin the literature.However,theirobservedHERoverpotentialsweremuchhigherthanthoseweobserved.Thus,this workdemonstratesa noveldirectionfor the preparationof low-costHERelectrodes,yet withverylowoverpotentialsby coatingonlya minorportion(28%)of the conductingsubstratewithverysmallamountsof PtPdalloynanoparticles.
2019
Generation of hydrogen fuel through electrochemical water splitting is the most eco-friendly approach. Herein we have developed a core-shell material consisting NiCo-LDH deposited on Cu wires grown on Cu mesh which surpasses the activity of 40% Pt/C. This particuar catalyst requires 15 and 27 mV overpotential for hydrogen evolution in alkaline and acidic medium, respectively, along with durability at high current density and flexibility. Density of state calculation explains the reason of better activity of Cu wire than Cu mesh.
RECENT, 2023
The continual increase in world population and lifestyle standards has led to a seminal growth in global energy consumption amounting to about 90% of global energy as fossil fuels supply the transportation and industrial sectors. This led to high emission of greenhouse gases including carbon dioxide, resulting in a substantial depletion of carbon-based resources that could be otherwise used to produce valuable chemicals. In 2013, worldwide energy consumption was 17 TW and is expected to at least double by 2050. This research studied the rational design of porous binary Pt-based nanodendrites as an efficient catalytic system for electrochemical driven water splitting for energy production. Porous Pt-Pd nanodendrites were typically synthesized by the reduction of the metal precursors by L-ascorbic acid (AA) in the presence of PVP as a structure-directing agent under ultrasonication. The Platinum-Palladium (Pt-Pd) was used as a catalyst in water splitting technique for hydrogen production and compared with commercial Pt/C catalyst. Several tests were done on the samples including Cyclic Voltammetry (CV), Linear Sweep Voltammetry (LSV), IT, ET to measure the energy rate and the characterization at the last step.