Publications

Export 73 results:
Sort by: Author Title Type [ Year  (Desc)]
2020
Al-Akraa, I. M., and A. M. Mohammad, "A spin-coated TiOx/Pt nanolayered anodic catalyst for the direct formic acid fuel cells", Arabian Journal of Chemistry, vol. In Press: Elsevier B.V., 2019, 2020. AbstractWebsite

The CO poisoning of the platinum anodic catalyst which typically functions the catalytic deterioration of the direct formic acid fuel cells could be minimized with a simple modification for Pt with titanium oxide. The fabrication scheme involved the spin-coating of a Ti precursor onto a Pt thin layer that was physically sputtered onto a Si substrate. The whole assembly was subjected to a post-annealing processing to produce the TiOx layer (60 nm) in a porous structure (mostly Anatase) atop of the Pt surface. The porous nature of the TiOx layer permitted the participation of Pt in the electrocatalysis of the formic acid electro–oxidation (FAO). The annealing temperature was critical in identifying the catalytic efficiency and durability of the catalyst toward the FAO. Interestingly, if compared to bare-Pt substrates, the TiOx-modified catalysts could successfully steer the FAO toward the direct dehydrogenation (favorable and less energetic) pathway with more than an order of magnitude increase in the catalytic activity. It also provided a great opportunity for the mitigation of poisoning CO; concurrently with a lowering (~0.3 V) in the onset potential of the FAO. The scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction spectroscopy (XRD), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques were all combined to evaluate, respectively, the catalyst's morphology, composition, crystal structure and activity and further to understand the role of the TiOx in the catalytic enhancement. © 2019 The Author(s)

2019
Asal, Y. M., I. M. Al-Akraa, A. M. Mohammad, and M. S. El-Deab, "A competent simultaneously co-electrodeposited Pt-MnOx nanocatalyst for enhanced formic acid electro-oxidation", Journal of the Taiwan Institute of Chemical Engineers, vol. 96: Taiwan Institute of Chemical Engineers, pp. 169 - 175, 2019. AbstractWebsite

In this paper, a new methodology replacing the typical sequential layer-by-layer immobilization, i.e., simultaneous co-electrodeposition protocol is proven eminent for assembling efficient binary nanoelectrocatalysts for formic acid (FA) electro-oxidation (FAO). This strategy is successful to integrate homogeneously Pt nanoparticles (nano-Pt; essential component for FA adsorption/oxidation) with manganese oxide nanowires (nano-MnOx; a CO poisoning alleviator) in a single blend avoiding the poisoning CO adsorption at the catalyst surface. The molar ratio of the catalyst's ingredients (Pt:Mn) in the deposition bath is critical in identifying the catalyst's composition of the prepared binary catalyst and thus, a molar ratio of (1:8) is optimum yielding the highest catalytic activity. It is believed that adjusting the catalyst's composition could preferably act against the adsorption of poisoning CO intermediate and/or providing an electronic support to the desired (low over potential) direct dehydrogenation pathway of FAO to CO 2 . © 2018 Taiwan Institute of Chemical Engineers

Asal, Y. M., I. M. Al-Akraa, A. M. Mohammad, and M. S. El-Deab, "Design of efficient bimetallic Pt–Au nanoparticle-based anodes for direct formic acid fuel cells", International Journal of Hydrogen Energy, vol. 44, issue 7: Elsevier Ltd, pp. 3615 - 3624, 2019. AbstractWebsite

Formic acid (FA) electro-oxidation (FAO) was investigated at a binary catalyst composed of Pt (PtNPs) and Au (AuNPs) nanoparticles which were electrodeposited simultaneously onto a glassy carbon (GC) substrate. The catalytic activity of the binary modified catalyst toward FAO was significantly influenced by the relative molar ratio of PtNPs and AuNPs. Interestingly, the catalyst with a molar ratio (1:1) of PtNPs and AuNPs showed the highest activity toward the favorable pathway of FAO (ca. 26 times increase in the direct peak current concurrently with a ca. 133 mV negative shift in the onset potential). Such enhancement was believed originating from the outstanding improvement of charge transfer during FAO via the desirable “non-poisoning” pathway along with a significant mitigation of CO poisoning at the electrode surface. The diversity of techniques (cyclic voltammetry, chronoamperometry, electrochemical impedance spectroscopy, field-emission scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffraction) employed in this investigation offered opportunities to assess and interpret the catalyst's activity and stability and to possess a deliberated overview about its morphology, composition and structure. © 2018 Hydrogen Energy Publications LLC

El-Nowihy, G. H., A. M. Mohammad, M. A. Sadek, M. M. H. Khalil, and M. S. El-Deab, "EIS-activity correlation for the electro-oxidation of ethylene glycol at nanoparticles-based electrocatalysts", Journal of the Electrochemical Society, vol. 166, issue 6: Electrochemical Society Inc., pp. F364 - F376, 2019. AbstractWebsite

Enhanced catalysis of ethylene glycol electro-oxidation (EGO) is reported at a ternary CoOx/NiOx/Pt catalyst in which Pt nanoparticles (nano-Pt), nickel oxide nanoflowers (nanoNiOx), and cobalt oxide nanoparticles (nano-CoOx); are respectively electrodeposited onto a glassy carbon (GC) substrate. The electrocatalytic activity of the catalyst toward EGO depends on the catalyst's composition, loading sequence and loading level besides the electrolyte's pH and temperature. A detailed morphological, compositional, and structural inspection for the catalyst is achieved by FE-SEM, energy dispersive X-ray spectroscopy, and X-ray diffraction, respectively. Cyclic voltammetry is employed to ensure the successful electrodeposition of the catalyst's ingredients and to assess its activity. The superiority of the CoOx/NiOx/Pt/GC catalyst over a series of catalysts employing different ingredients and/or deposition sequence is demonstrated. It supports a larger (ca. fourfold) oxidation peak current, and a significant (ca. -330 mV) negative shift in the onset potential of EGO together with a much more enhanced long-term stability toward continuous electrolysis when compared to the Pt catalyst. The novelty of this investigation extends to employing the electrochemical impedance spectroscopy (EIS) as a probe that provides important information about the reaction pathway of EGO. Interestingly, the maximum capacitance obtained at the CoOx/NiOx/Pt/GC catalyst (coincides with the EGO peak current) is fivefold higher than that obtained at the Pt/GC catalyst at -0.35 V vs. Ag/AgCl. Formic acid and oxalic acid were the major products of EGO, as revealed by high performance liquid chromatography. © 2019 The Electrochemical Society.

Al-Akraa, I. M., Y. M. Asal, and A. M. Mohammad, "Facile synthesis of a tailored-designed AU/PT nanoanode for enhanced formic acid, methanol, and ethylene glycol electrooxidation", Journal of Nanomaterials, vol. 2019: Hindawi Limited, 2019. AbstractWebsite

The recent revolution in nanoscience and global energy demand have motivated research in liquid fuel cells (LFCs) due to their enhanced efficiency, moving flexibility, and reduced contamination. In line with this advancement, a glassy carbon (GC) electrode was modified with platinum (PtNPs) and gold (AuNPs) nanoparticles to fabricate a nanosized anode for formic acid, methanol, and ethylene glycol electrooxidation (abbreviated, respectively, to FAO, MO, and EGO), of the key anodic reactions of LFCs. The deposition sequence of the catalyst’s layers was important where the Au/Pt/GC electrode (in which PtNPs were directly deposited onto the GC surface followed by AuNPs—surface coverage ≈ 32%) exhibited the best catalytic performance. The catalytic performance of the Au/Pt/GC anode excelled (at least threefold) its value obtained at the Pt/GC anode with regard to FAO and EGO, if the oxidation peak currents were compared. This enhancement got reduced to 1.4 times in the case of MO, but the large decrease (− 220 mV) in the onset potential of MO provided compensation. The role of AuNPs in the Au/Pt/GC catalyst was principal in boosting its catalytic performance as it immunized the underlying PtNPs against CO poisoning which is associated with the release of CO as an intermediate during the oxidation. Interestingly, AuNPs succeeded in interrupting the contiguity of the Pt surface sites required for CO adsorption during FAO, MO, and EGO and, thus, presage preventing the deterioration of the catalytic performance of their corresponding LFCs. Copyright © 2019 Islam M. Al-Akraa et al.

Al-Akraa, I. M., T. Ohsaka, and A. M. Mohammad, "A promising amendment for water splitters: Boosted oxygen evolution at a platinum, titanium oxide and manganese oxide hybrid catalyst", Arabian Journal of Chemistry, vol. 12, issue 7: Elsevier B.V., pp. 897 - 907, 2019. AbstractWebsite

A hybrid catalyst composed of a platinum thin layer and modified with manganese oxide (MnOx) is recommended for the oxygen evolution reaction (OER). The Pt layer of the catalyst was physically sputtered onto a TiOx-coated Si substrate (this TiOx layer was sputtered inbetween the Si substrate and Pt layer to improve their adhesion and prevent their mutual diffusion). On top of the Pt layer, another thin TiOx layer (∼60 nm) was spun before the electrochemical deposition of MnOx. The investigation focused primarily to evaluate the impact of the catalyst's annealing in oxygen atmosphere on its catalytic activity toward OER. Interestingly, before the modification with MnOx, a large catalytic enhancement both in activity (∼228 mV negative shift at 20 mA cm−2 if compared to conventional bare Pt catalysts) and stability was achieved at the catalyst annealed at 600 °C toward OER in 0.5 M KOH. Surprisingly, the addition of MnOx to the catalyst synergized a boosted activity amplifying the negative shift to 470 mV at the same current density. Bunch of materials and electrochemical techniques were combined to reveal important remarks about the catalyst's morphology, structure, composition and intrinsic activity which was attributed to electronic rather than geometric factors. © 2019 King Saud University

2018
Al-Qodami, B. A., H. H. Farrag, S. Y. Sayed, N. K. Allam, B. E. El-Anadouli, and A. M. Mohammad, "Bifunctional tailoring of platinum surfaces with earth abundant iron oxide nanowires for boosted formic acid electro-oxidation", Journal of Nanotechnology, vol. 2018: Hindawi Limited, 2018. AbstractWebsite

To expedite the marketing of direct formic acid fuel cells, a peerless inexpensive binary FeOx/Pt nanocatalyst was proposed for formic acid electro-oxidation (FAO). The roles of both catalytic ingredients (FeOx and Pt) were inspired by testing the catalytic performance of FAO at the FeOx/Au and FeOx/GC analogies. The deposition of FeOx proceeded electrochemically with a post-activating step that identified the catalyst's structure and performance. With a proper adaptation for the deposition and activation processes, the FeOx/Pt nanocatalyst succeeded to mitigate the typical CO poisoning that represents the principal element deteriorating the catalytic performance of the direct formic acid fuel cells. It also provided a higher (eightfold) catalytic efficiency than the bare Pt substrates toward FAO with a much better durability. Field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD) were all employed to inspect, respectively, the surface morphology, bulk composition, and crystal structure of the catalyst. The electrochemical impedance spectra could correlate the charge transfer resistances for FAO over the inspected set of catalysts to explore the role of FeOx in mediating the reaction mechanism. © 2018 Bilquis Ali Al-Qodami et al.

Asal, Y. M., I. M. Al-Akraa, A. M. Mohammad, and M. S. El-Deab, "A competent simultaneously co-electrodeposited Pt-MnOx nanocatalyst for enhanced formic acid electro-oxidation", Journal of the Taiwan Institute of Chemical Engineers: Taiwan Institute of Chemical Engineers, 2018. Abstract

In this paper, a new methodology replacing the typical sequential layer-by-layer immobilization, i.e., simultaneous co-electrodeposition protocol is proven eminent for assembling efficient binary nanoelectrocatalysts for formic acid (FA) electro-oxidation (FAO). This strategy is successful to integrate homogeneously Pt nanoparticles (nano-Pt; essential component for FA adsorption/oxidation) with manganese oxide nanowires (nano-MnOx; a CO poisoning alleviator) in a single blend avoiding the poisoning CO adsorption at the catalyst surface. The molar ratio of the catalyst's ingredients (Pt:Mn) in the deposition bath is critical in identifying the catalyst's composition of the prepared binary catalyst and thus, a molar ratio of (1:8) is optimum yielding the highest catalytic activity. It is believed that adjusting the catalyst's composition could preferably act against the adsorption of poisoning CO intermediate and/or providing an electronic support to the desired (low over potential) direct dehydrogenation pathway of FAO to CO2. © 2018 Taiwan Institute of Chemical Engineers

Al-Akraa, I. M., A. M. Mohammad, M. S. El-Deab, and B. E. El-Anadouli, "Fabrication of CuOx-Pd nanocatalyst supported on a glassy carbon electrode for enhanced formic acid electro-oxidation", Journal of Nanotechnology, vol. 2018: Hindawi Limited, 2018. AbstractWebsite

Formic acid (FA) electro-oxidation (FAO) was investigated at a binary catalyst composed of palladium nanoparticles (PdNPs) and copper oxide nanowires (CuOxNWs) and assembled onto a glassy carbon (GC) electrode. The deposition sequence of PdNPs and CuOxNWs was properly adjusted in such a way that could improve the electrocatalytic activity and stability of the electrode toward FAO. Several techniques including cyclic voltammetry, chronoamperometry, field-emission scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction were all combined to report the catalyst's activity and to evaluate its morphology, composition, and structure. The highest catalytic activity and stability were obtained at the CuOx/Pd/GC electrode (with PdNPs directly deposited onto the GC electrode followed by CuOxNWs with a surface coverage, of ca. 49%). Such enhancement was inferred from the increase in the peak current of direct FAO (by ca. 1.5 fold) which associated a favorable negative shift in its onset potential (by ca. 30 mV). The enhanced electrocatalytic activity and stability (decreasing the loss of active material by ca. 1.5-fold) of the CuOx/Pd/GC electrode was believed originating both from facilitating the direct oxidation (decreasing the time needed to oxidize a complete monolayer of FA, increasing turnover frequency, by ca. 2.5-fold) and minimizing the poisoning impact (by ca. 71.5%) at the electrode surface during FAO. © 2018 Islam M. Al-Akraa et al.

Farrag, H. H., A. A. Abbas, S. Y. Sayed, H. H. Alalawy, B. E. El-Anadouli, A. M. Mohammad, and N. K. Allam, "From Rusting to Solar Power Plants: A Successful Nano-Pattering of Stainless Steel 316L for Visible Light-Induced Photoelectrocatalytic Water Splitting", ACS Sustainable Chemistry and Engineering, vol. 6, issue 12: American Chemical Society, pp. 17352 - 17358, 2018. AbstractWebsite

A novel propitious nanoporous anodized stainless steel 316L (NASS316L) photoanode was developed for water splitting. The anodization could successfully produce a uniform nanoporous (- 90 nm in pore diameter) array (- 2.0 μm thick) of NASS316L with a high pore density. Several techniques, including FESEM, EDX, XRD, XPS, ICP-OES, and UV-vis-NIR spectrophotometry, were employed to characterize the catalyst and to assess and interpret its activity toward water splitting. Surprisingly, the NASS316L retained almost the same composition of the bare stainless steel 316L, which recommended a symmetric dealloying mechanism during anodization. It also possessed a narrow band gap energy (1.77 eV) and a unique photoelectrocatalytic activity (- 4.1 mA cm-2 at 0.65 V versus Ag/AgCl, 4-fold to that of α-Fe2O3) toward water splitting. The onset potential (-0.85 V) in the photocurrent-voltage curve of the NASS316L catalyst demonstrated a negative shift in its Fermi level when compared to α-Fe2O3. The high (23% at 0.2 V vs Ag/AgCl) incident-photon-to-current conversion efficiency and the robust durability revealed from the in situ analysis of the produced H2 gas continued recommending the peerless inexpensive and abundant NASS316L catalyst for potential visible-induced solar applications. © 2018 American Chemical Society.

Hassan, M. A., A. M. Mohammad, T. A. Salah Eldin, and B. E. El-Anadouli, "A promising hydroxyapatite/graphene hybrid nanocomposite for methylene blue dye's removal in wastewater treatment", International Journal of Electrochemical Science, vol. 13, issue 8: Electrochemical Science Group, pp. 8222 - 8240, 2018. AbstractWebsite

A novel hydroxyapatite/graphene hybrid nanocomposite (HAp/G) was developed as a competent adsorbent for the removal of methylene blue (MB) dye in wastewater treatment. The adsorption was pursued in a batch process that followed pseudo-second-order kinetics. Several techniques including the high resolution transmission electron microscopy (HR-TEM), energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD), Fourier transform infrared spectrophotometry (FTIR) and Zeta potential (Electrokinetic potential) measurements were employed to evaluate the topography, composition, crystal structure, functionality and stability of the developed sorbent. The equilibrium concentration of MB was estimated using UV-Vis spectrophotometry. The impact of MB's initial concentration, HAp/G's dosage and solution pH on the adsorption capacity of HAp/G was investigated. Interestingly, superior removal efficiencies (up to 99.9%) for MB were obtained using HAp/G. Typically, the maximum sorption capacity (qm) of HAp/G to MB was 333.3 mg/g, which excelled several previously-reported achievements at other sorbents. The harmony of data fitting with the Langmuir isotherm was successful. © 2018 The Authors.

Mohammad, A. M., I. M. Al-Akraa, and M. S. El-Deab, "Superior electrocatalysis of formic acid electro-oxidation on a platinum, gold and manganese oxide nanoparticle-based ternary catalyst", International Journal of Hydrogen Energy, vol. 43, issue 1: Elsevier Ltd, pp. 139 - 149, 2018. AbstractWebsite

A novel “MnOx/Au/Pt” ternary nanocatalyst is recommended for formic acid electro-oxidation (FAO), the principal anodic reaction in direct formic acid fuel cells (DFAFCs). The protocol employed to prepare the catalyst utilized the sequential (layer-by-layer) electrodeposition of Pt (nano-Pt), Au (nano-Au) and manganese oxide (nano-MnOx) nanoparticles onto the surface of a glassy carbon (GC) support. The nano-Au enhanced the catalytic performance by changing the surface geometry to inhibit the adsorption of poisoning CO, which is a typical intermediate in the reaction mechanism of FAO, producing a potential deterioration of the catalytic performance of DFAFCs. On the other hand, nano-MnOx could successfully mediate the mechanism of FAO by accelerating the charge transfer and imparting an enhanced catalytic stability during long continuous operation. Interestingly, with this modification of the Pt/GC electrode by nano-Au and nano-MnOx, a significant (ca. 67 times that obtained at the Pt/GC electrode) enhancement in the catalytic activity toward FAO was achieved. © 2017 Hydrogen Energy Publications LLC

2017
Mohammad, A. M., T. A. Salah Eldin, M. A. Hassan, and B. E. El-Anadouli, "Efficient treatment of lead-containing wastewater by hydroxyapatite/chitosan nanostructures", Arabian Journal of Chemistry, vol. 10, issue 5: Elsevier B.V., pp. 683 - 690, 2017. AbstractWebsite

The development of hydroxyapatite nanorods (nHAp) and hydroxyapatite/chitosan nanocomposite (nHApCs) was sought as potential sorbents for the removal of lead ions from aqueous lead-containing solutions in a batch adsorption experiment. The high resolution transmission electron microscopy, energy dispersive X-ray analysis, X-ray diffraction, Fourier transform infrared spectrophotometry and Zeta potential measurements were all combined to reveal the morphology, composition, crystal structure, functionality and stability of the prepared sorbents. The equilibrium concentration of Pb2+ ions was identified by the atomic absorption spectrophotometry. The kinetics of the sorption process was investigated together with the influence of initial lead ions concentration, sorbent dosage and solution pH on the sorption capacity. The sorption process followed pseudo-second-order kinetics, where 20 min was quite enough to attain equilibrium. Two models of adsorption isotherms (Freundlich and Langmuir) were employed to correlate the data in order to understand the adsorption mechanism. Interestingly, in one of the experiments, for a 200 mL solution (pH = 5.6) containing 100 ppm lead ions, a sorbent dosage of 0.4 g nHAp could achieve a complete removal for lead ions. However, typically, the sorption capacities of nHAp and nHApCs to lead ions were 180 and 190 mg/g respectively, which appear excellent for lead removal. © 2015

Al-Akraa, I. M., A. M. Mohammad, M. S. El-Deab, and B. E. El-Anadouli, "Flower-shaped gold nanoparticles: Preparation, characterization, and electrocatalytic application", Arabian Journal of Chemistry, vol. 10, issue 6: Elsevier B.V., pp. 877 - 884, 2017. AbstractWebsite

The modification of a glassy carbon electrode with gold nanoparticles was pursued, characterized, and examined for electrocatalytic applications. The fabrication process of this electrode involved assembling the gold nanoparticles atop of amino group grafted glassy carbon electrode. The scanning electron microscopy indicated the deposition of gold nanoparticles in flower-shaped nanostructures with an average particle size of ca. 150 nm. Interestingly, the electrode exhibited outstanding enhancement in the electrocatalytic activity toward the oxygen evolution reaction, which reflected from the large negative shift (ca. 0.8 V) in its onset potential, in comparison with that observed at the bulk unmodified glassy carbon and gold electrodes. Alternatively, the Tafel plot of the modified electrode revealed a significant increase (∼one order of magnitude) in the apparent exchange current density of the oxygen evolution reaction upon the modification, which infers a faster charge transfer. Kinetically, gold nanoparticles are believed to facilitate a favorable adsorption of OH− (fundamental step in oxygen evolution reaction), which allows the charge transfer at reasonably lower anodic polarizations. © 2015 The Authors

El-Nagar, G. A., A. M. Mohammad, M. S. El-Deab, and B. E. El-Anadouli, "Propitious Dendritic Cu2O-Pt Nanostructured Anodes for Direct Formic Acid Fuel Cells", ACS Applied Materials and Interfaces, vol. 9, issue 23: American Chemical Society, pp. 19766 - 19772, 2017. AbstractWebsite

This study introduces a novel competent dendritic copper oxide-platinum nanocatalyst (nano-Cu2O-Pt) immobilized onto a glassy carbon (GC) substrate for formic acid (FA) electro-oxidation (FAO); the prime reaction in the anodic compartment of direct formic acid fuel cells (DFAFCs). Interestingly, the proposed catalyst exhibited an outstanding improvement for FAO compared to the traditional platinum nanoparticles (nano-Pt) modified GC (nano-Pt/GC) catalyst. This was evaluated from steering the reaction mechanism toward the desired direct route producing carbon dioxide (CO2); consistently with mitigating the other undesired indirect pathway producing carbon monoxide (CO); the potential poison deteriorating the catalytic activity of typical Pt-based catalysts. Moreover, the developed catalyst showed a reasonable long-term catalytic stability along with a significant lowering in onset potential of direct FAO that ultimately reduces the polarization and amplifies the fuel cell's voltage. The observed catalytic enhancement was believed to originate bifunctionally; while nano-Pt represented the base for the FA adsorption, nanostructured copper oxide (nano-Cu2O) behaved as a catalytic mediator facilitating the charge transfer during FAO and providing the oxygen atmosphere inspiring the poison's (CO) oxidation at relatively lower potential. Surprisingly, moreover, nano-Cu2O induced a surface retrieval of nano-Pt active sites by capturing the poisoning CO via "a spillover mechanism" to renovate the Pt surface for the direct FAO. Finally, the catalytic tolerance of the developed catalyst toward halides' poisoning was discussed. © 2017 American Chemical Society.

Abd El-Moghny, M. G., H. H. Alalawy, A. M. Mohammad, A. A. Mazhar, M. S. El-Deab, and B. E. El-Anadouli, "Conducting polymers inducing catalysis: Enhanced formic acid electro-oxidation at a Pt/polyaniline nanocatalyst", International Journal of Hydrogen Energy, 2017.
El-Nowihy, G. H., A. M. Mohammad, M. M. H. Khalil, M. A. Sadek, and M. S. El-Deab, "Investigating a sequentially assembled MnOx/Pt nanocatalyst as a potential anode for ethylene glycol fuel cells", International Journal of Electrochemical Science, vol. 12, pp. 62-73, 2017.
El-Nowihy, G. H., A. M. Mohammad, M. M. H. Khalil, M. A. Sadek, and M. S. El-Deab, "Promising ethylene glycol electro-oxidation at tailor-designed NiOx/Pt nanocatalyst", International Journal of Hydrogen Energy, 2017.
2016
El-Nagar, G. A., A. M. Mohammad, M. S. El-Deab, and B. E. El-Anadouli, "Novel fuel blends facilitating the electro-oxidation of formic acid at a nano-Pt/GC electrode", RSC Advances, vol. 6, issue 35, pp. 29099-29105, 2016.
2015
Al-Akraa, I. M., A. M. Mohammad, M. S. El-Deab, and B. S. El-Anadouli, "Advances in direct formic acid fuel cells: Fabrication of efficient Ir/Pd nanocatalysts for formic acid electro-oxidation", International Journal of Electrochemical Science, vol. 10, issue 4: Electrochemical Science Group, pp. 3282 - 3290, 2015. AbstractWebsite

The modification of a glassy carbon (GC) electrode with palladium (PdNPs) and Iridium (IrNPs) nanoparticles is targeted to develop efficient anodes for formic acid electro?oxidation (FAO). The deposition order of PdNPs and IrNPs is appropriately adjusted in such a way that could improve the electrocatalytic activity and stability of the electrode towards FAO. The highest catalytic activity and stability are obtained at the Ir/Pd/GC electrode (with PdNPs directly deposited onto the GC electrode followed with IrNPs). Such enhancement is manifested in the increase of the oxidation current of formic acid (FA) together with a favorable negative shift in the onset potential of FAO. This marvelous enhancement is believed to originate from the electronic enhancement and/or the bi-functional mechanism of IrNPs to the Pd-based catalysts. © 2015 The Authors.

El-Refaei, S. M., G. A. El-Nagar, A. M. Mohammad, and B. E. El-Anadouli, "Electro-oxidation of formic acid, glucose, and methanol at nickel oxide nanoparticle modified platinum electrodes", Progress in Clean Energy, Volume 1: Analysis and Modeling: Springer International Publishing, pp. 595 - 604, 2015. Abstract

The current study presents a comparison for the electro-oxidation of formic acid (FA), glucose (GL), and methanol (ME) at nickel oxide nanoparticles (NiOx) modified electrodes. The modification with NiOx was pursed onto a bare glassy carbon (GC) and Pt-modified (Pt/GC) electrodes electrochemically, and the catalytic activity was measured in 0.3 M NaOH. Cyclic voltammetry (CV), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX) are all used to provide a concrete characterization of the prepared electrodes. A catalytic enhancement of GL oxidation (GLO) and ME oxidation (MEO) was observed at the NiOx-modified GC (NiOx/GC) electrode, while the same electrode did not show any activity towards FA oxidation (FAO), revealing that FAO is substrate dependent. On the other hand, assembling NiOx onto the Pt/GC electrode assisted in improving the catalytic activity of all reactions (GLO, MEO, and FAO). The catalytic enhancement observed at the NiOx/Pt/GC electrode for GLO, MEO, and FAO was not only confined in the large increase of the oxidation current but also in a negative shift in the onset potential of the oxidation reaction. We believe NiOx could successfully play an essential role in this catalytic enhancement, presumably via participation in these reactions in a way facilitating the charge transfer or providing the oxygen atmosphere necessary for promoting an oxidative removal for unwanted poisoning species. © Springer International Publishing Switzerland 2015.

Al-Akraa, I. M., A. M. Mohammad, M. S. El-Deab, and B. E. El-Anadouli, "Electrocatalysis by design: Synergistic catalytic enhancement of formic acid electro-oxidation at core-shell Pd/Pt nanocatalysts", International Journal of Hydrogen Energy, vol. 40, issue 4: Elsevier Ltd, pp. 1789 - 1794, 2015. AbstractWebsite

The modification of a glassy carbon (GC) electrode with palladium (PdNPs) and platinum (PtNPs) nanoparticles is targeted to fabricate efficient anodes for the formic acid (FA) electro-oxidation (FAO). A proper adjustment of the deposition sequence and loading of PdNPs (as a shell) over PtNPs (as a core) of the nanocatalyst could eventually enhance its electrocatalytic activity towards FAO in such a way suppressing the CO poisoning pathway. It also improved the prolonged mechanical stability of the catalyst over a prolonged time of continuous electrolysis of FA. The highest oxidation efficiency, in terms of the catalytic activity and stability, is obtained at the Pd/Pt/GC electrode (with PtNPs directly deposited onto the GC electrode followed by ca. 6 monolayers of PdNPs). The role of PdNPs and PtNPs in the catalytic enhancement is discussed. © 2014 Hydrogen Energy Publications, LLC.

Al-Akraa, I. M., A. M. Mohammad, M. S. El-Deab, and B. E. El-Anadouli, "Electrocatalysis by nanoparticle: Enhanced electro-oxidation of formic acid at NiOx-Pd binary nanocatalysts", Journal of the Electrochemical Society, vol. 162, issue 10: Electrochemical Society Inc., pp. F1114 - F1118, 2015. AbstractWebsite

This study addresses formic acid (FA) electro-oxidation (FAO) at a binary catalyst composed of palladium (PdNPs) and nickel oxide (nano-NiOx) nanoparticles electrodeposited onto a glassy carbon (GC) electrode. The deposition sequence of PdNPs and nano-NiOx onto the GC electrode is properly adjusted in such a way that maximizes the electrode efficiency toward FAO. The highest catalytic activity and stability are obtained at the NiOx/Pd/GC electrode (with PdNPs directly deposited onto the GC electrode followed with nano-NiOx with an optimum surface coverage, γ, of ca. 41%). The enhancement is manifested in the increase of the oxidation peak current of FA together with a favorable negative shift of the onset potential of FAO. It is believed that nano-NiOx could facilitate the direct oxidation of FA via minimizing the amount of the poisoning species at the Pd surface. © 2015 The Electrochemical Society.

El-Nagar, G. A., A. M. Mohammad, M. S. El-Deab, and B. E. El-Anadouli, "Electrocatalysis of formic acid electro-oxidation at platinum nanoparticles modified surfaces with nickel and cobalt oxides nanostructures", Progress in Clean Energy, Volume 1: Analysis and Modeling: Springer International Publishing, pp. 577 - 594, 2015. Abstract

The present study proposes a novel promising binary catalyst for formic acid electro-oxidation (FAO); the main anodic reaction in direct formic acid fuel cells (DFAFCs). The catalyst is basically composed of two metal oxides of nickel and cobalt nanostructures (i.e., NiOx and CoOx) assembled onto a platinum nanoparticles (PtNPs)°modified glassy carbon (Pt/GC) electrode. Actually, FAO proceeds at bare Pt surfaces in two parallel routes; one of them is desirable (called direct or hydrogenation) and occurred at a low potential domain (Idp). While, the other (undesirable) involves the dehydration of formic acid (FA) at low potential domain to produce a poisoning intermediate (CO), which next be oxidized (indirect, Iind p) at a higher potential domain after the platinum surface becomes hydroxylated. Unfortunately, the peak current ratio (Idp/Iind p) of the two oxidation routes, which monitors the degree of the catalytic enhancement and the poisoning level, stands for bare Pt surfaces at a low value (less than 0.2). Interestingly, this ratio increased significantly as a result of the further modification of the Pt/GC electrode with NiOx and a binary mixture of both I d This highlights the essential role of these in promoting the direct FAO, presumably via a mediation process that ultimately improved the oxidation kinetics or through a catalytic enhancement for the oxidation of the poisoning CO at the low potential domain of the direct FAO. The effect of the deposition order of NiOx and CoOx on the catalytic activity was addressed and fount influencing. The addition of CoOx to the catalyst was really important, particularly in improving the catalytic stability of the catalyst towards a long-term continuous electrolysis experiment, which actually imitates the real industrial applications. © Springer International Publishing Switzerland 2015.

Mohammad, A. M., G. H. El-Nowihy, M. M. H. Khalil, and M. S. El-Deab, "Electrocatalytic oxidation of methanol at nanoparticle-based MnOx/NiOx/Pt ternary catalysts: Optimization of loading level and order of deposition", Journal of the Electrochemical Society, vol. 161, issue 14: Electrochemical Society Inc., pp. F1340 - F1347, 2015. AbstractWebsite

A nanoparticle-based ternary catalyst composed of Pt (nano-Pt), nickel oxide (nano-NiOx) and manganese oxide (nano-MnOx), all were assembled on a glassy carbon (GC) substrate, was developed for the direct methanol electro-oxidation reaction (MOR) in an alkaline medium. The electrocatalytic activity of the modified electrodes toward MOR depended on the loading level of nano-Pt, nano-NiOx and nano-MnOx onto the GC electrode. Moreover, the order of deposition of nano-NiOx and nano-MnOx has critically influenced the catalytic activity and stability of MOR. The highest electrocatalytic activity was obtained at the MnOx/NiOx/Pt/GC electrode with nano-Pt directly deposited onto the GC surface followed by nano-NiOx and nano-MnOx sequentially. The catalytic activity of MOR at this electrode was about five times higher than that obtained at Pt/GC electrode. The stability and the effect of the operating pH on the catalytic activity of the proposed catalyst were investigated. Several techniques such as the cyclic voltammetry, field-emission scanning electron microscopy and energy dispersive X-ray spectroscopy (EDS) were used to address the catalytic activity of the catalyst and to reveal its surface morphology and bulk composition. © 2014 The Electrochemical Society.

Tourism