Displacement triangular Ag/Pd nanoplate as methanol- tolerant electrocatalyst in oxygen reduction reaction

Porous triangular Ag/Pd nanoplates with different alloy ratios, including Ag₁₈Pd₁, Ag₁₈Pd_1.5, and Ag₁₈Pd₂, were successfully prepared by a galvanic displacement reaction. These alloy nanoplates were then used as methanol-tolerant electrocatalysts in an alkaline oxygen reduction reaction (ORR). Electrochemical measurements were conducted using an ultrathin film rotating ring-disk electrode. The mass activity was found to decrease in the order Ag₁₈Pd₁ > Ag₁₈Pd₂ > Ag₁₈Pd_1.5 > Pt nanoparticles > Pd nanoparticles, similar to an observation made in a past analysis of the nanoplates in an electrolyte of free methanol; this indicates that these nanoplate catalysts are more economical than Pd nanoparticles, and even Pt nanoparticles. Additionally, compared to the reactive direction in the case of Pt and Pd nanoparticles toward methanol oxidation in an ORR electrolyte with methanol, all Ag/Pd nanoplate catalysts experienced cathodic currents, which indicate that ORRs occurred even in the presence of methanol. Despite working in a methanol-tolerant solution, the prepared alloy nanoplates still exhibited high electroactivity.     

A complementary study on novel PdAuCo catalysts: Synthesis,characterization, direct formic acid fuel cell application,and exergy analysis

At present, Pd containing (10–40 wt%) multiwall carbon nanotube (MWCNT) supported Pd monometallic, Pd:Au bimetallic, and PdAuCo trimetallic catalysts are prepared via NaBH₄ reduction method to examine their formic acid electrooxidation activities and direct formic acid fuel cell performances (DFAFCs) when used as anode catalysts. These catalysts are characterized by advanced analytical techniques as N₂ adsorption and desorption, XRD, SAXS, SEM-EDX, and TEM. Electronic state of Pd changes by the addition of Au and Co. Moreover, formic acid electrooxidation activities of these catalysts measured by CV indicates that particle size changes in wide range play a major role in the formic acid electrochemical oxidation activity, ascribed the strong structure sensitivity of formic acid electrooxidation reaction. PdAuCo (80:10:10)/MWCNT catalyst displays the most significant current density increase. On the other hand, lower CO stripping peak potential obtained for PdAuCo (80:10:10)/MWCNT catalyst, attributed to the awakening of the Pd-adsorbate bond strength down to its optimum value, which favors higher electrochemical activity. DFAFCs performance tests and exergy analysis reveal that fuel cell performances increase with the addition of Au and Co which can be attributed to synergetic effect. Furthermore, temperature strongly influences the performance of formic acid fuel cell.     

Highly active carbon nanotube supported PdAu alloy catalysts for ethanol electrooxidation in alkaline environment

At present, ethanol electrooxidation study is performed on CNT supported Pd and PdAu catalysts to investigate the effect of Au addition to Pd towards the ethanol electrooxidation activity. NaBH₄ reduction method is employed for the synthesis of Pd/CNT, Pd₉₀Au₁₀/CNT, Pd₉₀Au₁₀/CNT, Pd₇₀Au₃₀/CNT, Pd₅₀Au₅₀/CNT, and Pd₄₀Au₆₀/CNT catalysts. These catalysts are characterized via advanced surface analytical techniques namely N₂ adsortion-desoprtion measurements,X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM). The characterization results revealed that Pd₉₀Au₁₀/CNT has 205.42 m²/g and 1.18 cm³/g BET surface area (m²/g) and pore volume (cm³/g), respectively. On the other hand, XRD and XPS results revealed that the electronic state of Pd₉₀Au₁₀/CNT catalyst changed by Au addition to Pd. TEM and HRTEM and elemental mapping results reveal that Pd and Au is homogeneously dispersed and alloying of Pd and Au is clearly observed, in agreement with the XRD and XPS results. Ethanol electrooxidation measurements in alkaline environment are performed by Cyclic Voltammetry (CV), Chronoamperometry (CA), Electrochemical impedance spectroscop (EIS) techniques. Pd₉₀Au₁₀/CNT displayed the highest specific and mass activity. The synergistic effect between Pd and Au at optimized metal ratio was utilized to obtain an improvement in specific activity. Furthermore, Pd₉₀Au₁₀/CNT showed the lowest charge transfer resistance (R_ct) and a long term stability. As a result, it is clear that PdAu catalyst is a promising catalyst for Alkaline Direct Ethanol Fuel Cells.     

Determination of optimum Pd:Ni ratio for PdxNi100‐x/CNTs formic acid electrooxidation catalysts synthesized via sodium borohydride reduction method

The main purpose of this study is to investigate the optimum Pd:Ni molar ratio for carbon nanotube–supported PdNi (Pd_xNi_100‐x/CNT) alloy catalysts toward formic acid electrooxidation (FAE). NaBH₄ reduction method was employed for the synthesis of Pd₉₀Ni₁₀/CNT, Pd₇₀Ni₃₀/CNT, Pd₅₀Ni₅₀/CNT, and Pd₄₀Ni₆₀/CNT. Synthesized catalysts were characterized by employing advanced surface analytical techniques, namely, X‐ray diffraction (XRD), transmission electron microscopy (TEM), N₂ adsorption‐desorption, and inductively coupled plasma–mass spectrometry (ICP‐MS). The characterization results showed that all catalysts were successfully synthesized at desired molar composition. Pd₉₀Ni₁₀/CNT displayed the highest specific and mass activities with 2.32 mA/cm² and 613.9 mA/mg Pd, respectively. Specific activity of the Pd₉₀Ni₁₀/CNT was found approximately 3.6, 2.3, 11.1, and 3.4 times higher than those of Pd₇₀Ni₃₀/CNT, Pd₅₀Ni₅₀/CNT, Pd₄₀Ni₆₀/CNT, and Pd/CNT, respectively. The synergistic effect between Pd and Ni at optimized metal ratio was utilized to obtain an improvement in specific activity. Furthermore, Pd₉₀Ni₁₀/CNT showed the lowest charge transfer resistance (R_ct) and a long‐term stability. To our knowledge, this is the first study reporting the optimization of atomic molar composition for Pd_xNi_100‐x/CNT catalysts toward FAE.     

Investigations of Pt modified Pd/C catalyst synthesized by one-pot galvanic replacement for formic acid electrooxidation

Pt modified Pd/C catalysts were synthesized through galvanic replacement method in a one-pot synthetic process, where the replacement reaction was influenced greatly by the presence of the haloids (Cl⁻ or Br⁻) in the solution. The catalysts with and without Pt modification were characterized with X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), energy dispersive X-Ray spectroscopy (EDX) and electrochemical tests. The modified state and atomic ratio of Pt to Pd due to the variation of synthetic conditions were confirmed by the physical characterizations. The variation in structure/surface composition of the Pt–Pd/C catalysts leaded to different reaction mechanism and varied the performance of formic acid electrooxidation, which were confirmed by the electrochemical tests. The Pd/C catalyst modified with Pt in the presence of Cl⁻ possesses satisfactory comprehensive performance, i.e. both stability and activity, for formic acid electrooxidation (FAEO). The results are of significance for designing catalysts for practical application of direct formic acid fuel cell and understanding mechanism of FAEO on noble metals composite structures.     

Carbon-supported Pd catalysts: Influences of nanostructure on their catalytic performances for borohydride electrochemical oxidation

In the present work, a Pd catalyst supported on multiwalled carbon nanotubes (MWCNTs) is successfully synthesized and its property as the anode material for borohydride oxidation is investigated. Compared with other carbon-supported Pd catalysts, the Pd/MWCNT catalyst exhibits improved polarization properties due to its smaller Pd particles dispersing homogeneously on carbon nanotubes. The hydrogen evolution behavior on the Pd/activated carbon sample is found to be very sensitive to the concentrations of NaOH and NaBH₄ in the solution. On the other hand, borohydride oxidation on Pd/carbon black and Pd/MWCNT displays reaction mechanisms near the 4e stoichiometry. It is thus supposed that the primary direct borohydride oxidation on Pd may be a 4e reaction. The simultaneous electro-oxidation of adsorbed hydrogen occurs conditionally, depending on its relative activity with the direct oxidation of BH₄⁻.     

A straightforward one-pot synthesis of Pd–Ag supported on activated carbon as a robust catalyst toward ethanol electrooxidation

Direct Ethanol Fuel Cells (DEFCs) have fascinated remarkable attention on account of their high current density and being environmentally friendly. Developing efficient and durable catalysts with a simple and fast method is a great challenge in the practical applications of DEFCs. To this end, the bimetallic Pd–Ag with adjustable Pd:Ag ratios were synthesized via a simple and one-pot strategy on activated carbon as a support in this study. The Pd–Ag/C catalysts with different molar ratios were synthesized by simultaneous reduction of Pd and Ag ions in the presence of the ethanolic sodium hydroxide as a green reducing agent for the first time. Several different methods, including FE-SEM, HR-TEM, XRD, XPS EDX, ICP-OES, and BET were used to confirm the structure and morphology of the catalysts. The performance of catalysts was also examined in ethanol oxidation. Obtained results of electrochemical experiments revealed that the Pd₃–Ag₁/C catalyst had superior catalytic activity (2911.98 mAmg^?1_Pd), durability, and long-stability compared to the other catalysts. The excellent catalytic characteristic can be attributed to the synergistic effect between Pd and Ag. We presume that our simple method have the chance to be utilized as a proper method for the synthesis of fuel cell catalysts.     

Hydrogen generation from sodium borohydride hydrolysis by multi-walled carbon nanotube supported platinum catalyst: A kinetic study

In this study, it is aimed to investigate hydrogen (H₂) generation from sodium borohydride (NaBH₄) hydrolysis by multi-walled carbon nanotube supported platinum catalyst (Pt/MWCNT) under various conditions (0–0.03 g Pt amount catalyst, 2.58–5.03 wt % NaBH₄, and 27–67 °C) in detail. For comparison, carbon supported platinum (Pt/C) commercial catalyst was used for H₂ generation experiments under the same conditions. The reaction rate of the experiments was described by a power law model which depends on the temperature of the reaction and concentrations of NaBH₄. Kinetic studies of both Pt/MWCNT and Pt/C catalysts were done and activation energies, which is the required minimum energy to overcome the energy barrier, were found as 27 kJ/mol and 36 kJ/mol, respectively. Pt/MWCNT catalyst is accelerated the reaction less than Pt/C catalyst while Pt/MWCNT is more efficient than Pt/C catalyst, they are approximately 98% and 95%, respectively. According to the results of experiments and the kinetic study, the reaction system based on NaBH₄ in the presence of Pt/MWCNT catalyst can be a potential hydrogen generation system for portable applications of proton exchange membrane fuel cell (PEMFC).     

Bimetallic Pd–Bi nanocatalysts derived from NaBH4 reduction of BiOCl and Pd2+ and exhibit highly efficient hydrogen production over formaldehyde solution

Using liquid formaldehyde as a carrier to obtain clean hydrogen is a promising method. The development of inexpensive catalysts with high activity and stability is crucial for this reaction. Herein, bimetallic Pd–Bi nanocatalysts with different Pd to Bi ratios were prepared through one step in-situ reduction of BiOCl and Pd²⁺ ions by sodium borohydride (NaBH₄). The effect of Pd/Bi ratios and reaction parameters such as formaldehyde concentration and sodium hydroxide concentration on hydrogen production performance were systematically studied. By optimizing the Pd contents in Pd–Bi nanocatalysts under the optimized reaction conditions, an much higher hydrogen (H₂) production rate of 472.2 mL min^?1g^?1 over Pd/BiOCl-3% under 298.15 K can be achieved, which is 4.01 times that of pure Pd nanoparticles (NPs) and much higher than most reported metal-based catalysts.     

Pre-deposited Co nanofilms promoting high alloying degree of PdxAu nanoparticles as electrocatalysts in alkaline media

High alloyed and well dispersed Pd_xAu nanoparticles are deposited on pre-deposited Co nanofilm substrates (Pd_xAu/Co-nanofilms/C) by using an immiscible ionic liquid (IL)/water interface. However, low alloyed Pd_xAu/C catalysts are formed without pre-deposited Co nanofilms through the same synthesis method. The high-alloyed Pd_xAu/Co-nanofilms/C catalysts demonstrate significantly increased activity for ethanol oxidation reaction (EOR) than low-alloyed Pd_xAu/C of the same Pd/Au composition, with the catalysts of low Pd/Au atom ratio (Pd:Au = 1:1) demonstrating the optimal activity. Notably, high alloyed degree of the Pd_xAu nanoparticles in the Pd_xAu/Co-nanofilms/C catalysts brings the lattice expansion of Pd, causing an up-shift of the d-band center, which results in the enhancement of OH⁻ adsorption and correspondingly promotes electro-oxidation of ethanol excluding the effect of Co nanofilm substrates. Differently, the enhancement activities of the Pd-Au bimetallic system for oxygen reduction reaction (ORR) are almost not affected by the alloying degree and only dependent on Pd/Au atom ratios, with the catalysts of low Pd/Au atom ratio (Pd:Au = 1:1) displaying the highest ORR mass activity, respectively. These results exhibit the specific dependence between the different electrochemical process and the physical parameters for the Pd-Au bimetallic system.     

Electrocatalysts supported on multiwalled carbon nanotubes for direct borohydride–hydrogen peroxide fuel cell

Electrocatalysts of Rh, Ru, Pt, Au, Ag, Pd, Ni, and Cu supported on multiwalled carbon nanotubes for direct borohydride–hydrogen peroxide fuel cells are investigated. Metal/γ-Al₂O₃ catalysts for NaBH₄ and H₂O₂ decomposition tests are manufactured and their catalytic activities upon decomposition are compared. Also, the effects of XC-72 and multiwalled carbon nanotube (MWCNT) carbon supports on fuel cell performance are determined. The performance of the catalyst with MWCNTs is better than that of the catalyst with XC-72 owing to a large amount of reduced Pd and the good electrical conductivity of MWCNTs. Finally, the effect of electrodes with various catalysts on fuel cell performance is investigated. Based on test results, Pd (anode) and Au (cathode) are selected as catalysts for the electrodes. When Pd and Au are used together for electrodes, the maximum power density obtained is 170.9 mW/cm² (25 °C).     

Carbon nanotubes-supported colloidal Ag-Pd nanoparticles as electrocatalysts toward oxygen reduction reaction in alkaline electrolyte

Ag-Pd nanoparticles with compositional ratios of 1:1 (Ag₁Pd₁), 2:1 (Ag₂Pd₁), and 4:1 (Ag₄Pd₁) and supported on multiwall carbon nanotubes (CNTs) were prepared by the self-regulated reduction of sodium dodecyl sulfate, and then, they were used as catalysts for oxygen reduction reactions (ORRs) in 1 M NaOH solution. Polarization curves showed that, among the prepared nanocatalysts, Ag₄Pd₁/CNT nanocatalysts showed higher activity. During the ORRs, two types of oxygen coverages given by the Temkin isotherm and Langmuir isotherm were observed for low and high overpotentials, respectively. Koutecky-Levich plots showed that the number of electrons involved in the ORRs catalyzed by Ag₁Pd₁/CNT, Ag₂Pd₁/CNT, and Ag₄Pd₁/CNT were 2.11, 1.88, and 2.25, respectively. These ORRs proceeded through a two-electron pathway. Polarization curve in the electrolyte with methanol revealed that Ag₄Pd₁/CNT has high methanol tolerance during ORRs.     

Surfactant-free room temperature synthesis of PdxPty/C assisted by ultra-sonication as highly active and stable catalysts for formic acid oxidation

Formic acid oxidation is usually catalyzed on PdPt bimetallic catalysts, which are synthesized by co-reduction of noble metal precursors in the presence of high molecular capping agents. In this work, surfactant-free Pd_xPt_y/C catalysts are synthesized by H₂ reduction in ethylene glycol assisted with ultrasonication vibration at room temperature. Nanoparticle agglomeration in the course of preparation has been sufficiently curbed by strong mechanical ultrasonication instead of traditionally-employed surfactants. As a result, “clean” surfactant-free Pd_xPt_y/C catalysts necessitate only simple washing before collection. The catalysts are characterized by transmission electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The compositionally optimized Pd₁₀₀Pt₁/C catalyst registers a mass activity of 3171 A g⁻¹ (Pt + Pd) for formic acid oxidation in 0.5 M H₂SO₄+0.5 M HCOOH, which lists one of the best results reported so far and surpasses that of a commercial Pd/C by 5.6 times. Stability of the catalysts is investigated by cyclic voltammetric as well as chronoamperometric evaluations. This work offers a convenient and environmentally benign room-temperature route to synthesize highly active and stable catalysts for formic acid oxidation.     

Design the PdCu/Ni2P electrocatalyst with high efficiency for ethanol oxidation reaction in alkaline media

To facilitate the electrocatalytic behavior of Direct Ethanol Fuel Cells (DEFCs), a sequence of bimetallic Pd_xCu_y/Ni₂P-C catalysts are synthesized via the microwave-assisted ethylene glycol reduction method. The results indicate that our designed Pd₂Cu/Ni₂P-C(1:1) catalyst owns high activity (3974.08 mA mg^?1_Pd), 8.3 times higher than the commercial Pd/C. The durability and the CO tolerance of the corresponding catalysts are also investigated by chronoamperometry (CA) and CO stripping measurements, implying Pd₂Cu/Ni₂P-C(1:1) shows good durability and the anti-CO poisoning ability for EOR in alkaline media. The electrochemical impedance spectra (EIS) analysis reveals lower charge transfer resistance for Pd₂Cu/Ni₂P-C(1:1). Combined with the results of XRD, HRTEM, XPS and electrochemical measurements, we found that the good electrocatalytic activity, CO tolerance and long-term durability of Pd₂Cu/Ni₂P-C(1:1) may be provided by the electronic and strain effect among Pd, Cu and Ni₂P, which will bring the downshift in the d-band center of catalysts and the weakened adsorption of intermediates.     

A “special” anhydrous system for the preparation of alloyed Pd1Ce0.5 nanonetworks catalyst supported on carbon nanotubes with high electrochemical oxidation activity for formic acid

Herein, Pd₁Ce_0.5 alloy nanonetworks (ANNs) on multi-walled carbon nanotubes (MWCNTs) supported bimetallic catalyst (referred to Pd₁Ce_0.5/MWCNTs-D) was prepared in deep eutectic solvents (DESs). The Pd₁Ce_0.5/MWCNTs-D catalyst shows remarkable catalytic performance toward formic acid oxidation (FAO) (1968.5 mA mg_Pd^?1) and better CO anti-poisoning capability compare with Pd/MWCNTs-D, Pd/MWCNTs-W (prepared in water) and commercial Pd/C catalysts. The excellent network structure and synergistic effect are the main reasons for the improvement of electrochemical activity of Pd₁Ce_0.5/MWCNTs-D catalyst. This study provides a new method for preparation of high performance Pd-based electrocatalysts for direct formic acid fuel cell (DFAFC) applications.     

A novel Central Composite Design based response surface methodology optimization study for the synthesis of Pd/CNT direct formic acid fuel cell anode catalyst

At present, carbon nanotube supported Pd catalysts are synthesized via NaBH₄ reduction method to investigate their electro catalytic activity thorough formic acid electro oxidation. In order to optimize the synthesis conditions such as %Pd amount (X₁), NaBH₄ amount (times, X₂), water amount (ml, X₃), and time (min., X₄), Central Composite Design (CCD) experiments are designed and determined by the Design-Expert program to determine the maximum observed current (mA/mgPd). Formic acid electro oxidation current density of the catalyst is computed by the model as 974.80 mA/mg Pd for the catalyst prepared at optimum operating conditions (41.14 for %Pd amount, 280.23 NaBH₄ amount, 26.80 ml water amount, and 167.14 min time) obtained with numerical optimization method in CCD. This computed value is very close to the experimentally measured value as 920 mA/mg Pd. Finally, formic acid fuel cell measurements were performed on the Pd/CNT catalyst prepared at optimum operating conditions and compared with the commercial Pd black and Pt black catalysts. As a result, Pd/CNT exhibits better performance compared to Pd black, revealing that Pd/CNT is a promising catalyst for the direct formic acid fuel cell measurements.     

Synthesis of PdNi catalysts for the oxidation of ethanol in alkaline direct ethanol fuel cells

Carbon-supported PdNi catalysts for the ethanol oxidation reaction in alkaline direct ethanol fuel cells are successfully synthesized by the simultaneous reduction method using NaBH₄ as reductant. X-ray diffraction characterization confirms the formation of the face-centered cubic crystalline Pd and Ni(OH)₂ on the carbon powder for the PdNi/C catalysts. Transmission electron microscopy images show that the metal particles are well-dispersed on the carbon powder, while energy-dispersive X-ray spectrometer results indicate the uniform distribution of Ni around Pd. X-ray photoelectron spectroscopy analyses reveal the chemical states of Ni, including metallic Ni, NiO, Ni(OH)₂ and NiOOH. Cyclic voltammetry and chronopotentiometry tests demonstrate that the Pd₂Ni₃/C catalyst exhibits higher activity and stability for the ethanol oxidation reaction in an alkaline medium than does the Pd/C catalyst. Fuel cell performance tests show that the application of Pd₂Ni₃/C as the anode catalyst of an alkaline direct ethanol fuel cell with an anion-exchange membrane can yield a maximum power density of 90 mW cm⁻² at 60 °C.     

High performance Pd-based catalysts for oxidation of formic acid

Two novel catalysts for anode oxidation of formic acid, Pd₂Co/C and Pd₄Co₂Ir/C, were prepared by an organic colloid method with sodium citrate as a complexing agent. These two catalysts showed better performance towards the anodic oxidation of formic acid than Pd/C catalyst and commercial Pt/C catalyst. Compared with Pd/C catalyst, potentials of the anodic peak of formic acid at the Pd₂Co/C and Pd₄Co₂Ir/C catalyst electrodes shifted towards negative value by 140 and 50 mV, respectively, meanwhile showed higher current densities. At potential of 0.05 V (vs. SCE), the current density for Pd₄Co₂Ir/C catalyst is as high as up to 13.7 mA cm⁻², which is twice of that for Pd/C catalyst, and six times of that for commercial Pt/C catalyst. The alloy catalysts were nanostructured with a diameter of ca. 3–5 nm and well dispersed on carbon according to X-ray diffraction (XRD) and transmission electron microscopy (TEM) measurements. The composition of alloy catalysts was analyzed by energy dispersive X-ray analysis (EDX). Pd₄Co₂Ir/C catalyst showed the highest activity and best stability making it the best potential candidate for application in a direct formic acid fuel cell (DFAFC).     

Effects of hydrazine addition on gas evolution and performance of the direct borohydride fuel cell

A fuel cell configuration using alkaline NaBH₄–N₂H₄ solutions as the fuel is suggested. Gas evolution behaviors and cell performances of alkaline NaBH₄–N₂H₄ solutions on different catalysts have been studied. It is found that gas evolution behaviors are influenced by the applied anodic catalysts and the concentration of NaBH₄ and N₂H₄. NaBH₄ is mainly electro-oxidized on Pd but N₂H₄ is mainly electro-oxidized on Ni and surface-treated Zr–Ni alloy when using NaBH₄–N₂H₄ solutions as the fuel and a composite of Pd, Ni and surface-treated Zr–Ni alloy as the anodic catalyst. The cyclic voltammetry results show that electrochemical oxidation potential of NaBH₄ is higher than that of N₂H₄. Adding hydrazine into alkaline sodium borohydride solutions can suppress gas evolution and improve the cell performance of the DBFC. The performances of fuel cells using NaBH₄–N₂H₄ solutions are comparable to that of fuel cell using N₂H₄ solution.     

Study of isotope effect on dehydrogenation kinetics of Pd based alloys using differential scanning calorimetry

Owing to the large hydrogen isotope effect, palladium and palladium based alloy are of great technological importance for their application in separation of hydrogen isotopes. The present study deals with the investigation of isotope effect on hydrogen desorption kinetics of Pd, Pd_0.77Ag_0.23 and Pd_0.77Ag_0.10Cu_0.13 alloys, using non-isothermal method by employing Differential Scanning Calorimetry (DSC). Pd_0.77Ag_0.23 and Pd_0.77Ag_0.10Cu_0.13 alloys were prepared by arc melting method and characterised by XRD, TXRF and EDS. Both the alloys are found to have FCC phase similar to Pd lattice. Prior to kinetic measurements, samples were activated by hydriding-dehydriding method. Hydrogen/deuterium desorption kinetic measurements were carried out at four different heating rates (8, 12, 16 and 20 K/min) and Kissinger plots were constructed from peak temperature of DSC curves. Activation energies for hydrogen/deuterium desorption from the corresponding hydride/deuteride were calculated from the slope of Kissinger plot which follows the order; Pd > Pd_0.77Ag_0.23 > Pd_0.77Ag_0.10Cu_0.13. Activation energy for deuterium desorption was found to be lower than that of hydrogen desorption and significant isotope effect was observed for the Pd_0.77Ag_0.10Cu_0.13 alloy which makes it a favorable candidate material for its application in hydrogen isotope separation, employing self-displacement gas chromatography.