Jehad Abed

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In hydrogen production, the anodic oxygen evolution reaction (OER) limits the energy conversion efficiency and also impacts stability in proton-exchange membrane water electrolyzers. Widely used Ir-based catalysts suffer from insufficient activity, while more active Ru-based catalysts tend to dissolve under OER conditions. This has been associated...

The oxygen evolution reaction (OER) limits the energy efficiency of electrocatalytic systems due to the high overpotential symptomatic of poor reaction kinetics; this problem worsens over time if the performance of the OER electrocatalyst diminishes during operation. Here, a novel synthesis of nanocrystalline Ni–Co–Se using ball milling at cryogeni...

Further improvements in the performance and cost-effectiveness of water electrolyzers are urgently needed to accelerate decarbonization of hydrogen production. Iridium-free oxygen evolution reaction (OER) electrocatalysts are needed that are active and durable under acidic conditions. Here we report Ru 0.6 Cr 0.2 Ti 0.2 O 2 , identified from a mach...

Renewable CH4 produced from electrocatalytic CO2 reduction is viewed as a sustainable and versatile energy carrier, compatible with existing infrastructure. However, conventional alkaline and neutral CO2-to-CH4 systems suffer CO2 loss to carbonates, and recovering the lost CO2 requires input energy exceeding the heating value of the produced CH4. H...

The energy efficiency of water electrolyzers is limited by the sluggish kinetics incurred by oxygen evolution reaction (OER) catalysts. Iridium oxide is a widely used OER catalyst that is both electrochemically active and stable, however, it proves uneconomic for large-scale application due to the scarcity and high cost of Iridium. Therefore, findi...

Performing CO2 reduction in acidic conditions enables high single-pass CO2 conversion efficiency. However, a faster kinetics of the hydrogen evolution reaction compared to CO2 reduction limits the selectivity toward multicarbon products. Prior studies have shown that adsorbed hydroxide on the Cu surface promotes CO2 reduction in neutral and alkalin...

RuO 2 is a highly active electrocatalyst for the oxygen evolution reaction (OER) but is unstable in acidic environments. We investigated the encapsulation of RuO 2 nanoparticles with semipermeable, nanoscopic silicon oxide (SiO x ) overlayers as a strategy to improve their stability. SiO x encapsulated RuO 2 (SiO x |RuO 2 ) electrodes were prepared...

It is of interest to extend the reach of CO2 and CO electrochemistry to the synthesis of products with molecular weights higher than the C1 and C2 seen in most prior reports carried out near ambient conditions. Here we present a cascade C1–C2–C4 system that combines electrochemical and thermochemical reactors to produce C4H10 selectively at ambient...

Acidic water electrolysis enables the production of hydrogen for use as a chemical and as a fuel. The acidic environment hinders water electrolysis on non-noble catalysts, a result of the sluggish kinetics associated with the adsorbate evolution mechanism, reliant as it is on four concerted proton-electron transfer steps. Enabling a faster mechanis...

Single atom catalysts (SACs) possess unique catalytic properties due to low-coordination and unsaturated active sites. However, the demonstrated performance of SACs is limited by low SAC loading, poor metal-support interactions, and nonstable performance. Herein, we report a macromolecule-assisted SAC synthesis approach that enabled us to demonstra...

Improving the dispersion of active sites simultaneous with the efficient harvest of photons is a key priority for photocatalysis. Crystalline silicon is abundant on Earth and has a suitable bandgap. However, silicon-based photocatalysts combined with metal elements has proved challenging due to silicon's rigid crystal structure and high formation e...

Direct electrolysis of pH‐neutral seawater to generate hydrogen is an attractive approach for storing renewable energy. However, due to the anodic competition between the chlorine evolution and the oxygen evolution reaction (OER), direct seawater splitting suffers from a low current density and limited operating stability. Exploration of catalysts...

Acetic acid is an important chemical feedstock. The electrocatalytic synthesis of acetic acid from CO2 offers a low-carbon alternative to traditional synthetic routes, but the direct reduction from CO2 comes with a CO2 crossover energy penalty. CO electroreduction bypasses this, which motivates the interest in a cascade synthesis approach of CO2 to...

Sluggish kinetics of the anodic oxygen evolution reaction (OER) and minor upstream upsets in feed water quality remain bottlenecks for efficient water electrolysis, which is exacerbated under near-neutral pH environments due to H2O dissociation. In this work, we report the introduction of a NiSx interlayer in a Co-(NiFe) oxide/nitride catalyst on n...

Multicarbon alcohols produced by electrochemical CO2 reduction (CO2RR) are attractive alternatives to fossil fuels; however, the selectivity towards alcohols in CO2RR remains low, a result of competing hydrocarbon (that is, ethylene) production. Here we report on Cu catalysts decorated with different alkaline earth metal oxides (MOs). We found that...

Colour-tuned phosphors are promising for advanced security applications such as multi-modal anti-counterfeiting and data encryption. The practical adoption of colour-tuned phosphors requires these materials to be responsive to multiple stimuli (e.g., excitation wavelength, excitation waveform, and temperature) and exhibit excellent materials stabil...

Colloidal quantum dots (CQDs) are promising materials for IR light detection due to their tunable bandgap and their solution processing; however, to date, the time response of CQD IR photodiodes has been inferior to that provided by Si and InGaAs. We reasoned that the high permittivity of II‐VI CQDs leads to slow charge extraction due to screening...

To enable the accelerated discovery of materials with desirable properties, it is critical to develop accurate and efficient search algorithms. Quantum annealers and similar quantum-inspired optimizers have the potential to provide accelerated computation for certain combinatorial optimization challenges. However, they have not been exploited for m...

The electrochemical CO2 reduction reaction (CO2RR) provides a route to store intermittent electricity in the form of fuels like methane. We reasoned that disrupting C-C coupling while maintaining high ∗CO coverage could enhance methane selectivity and suppress the hydrogen evolution reaction (HER). We studied the effect of doping CuAl, a material a...

The high-energy-density C3 fuel n-propanol is desired from CO2/CO electroreduction, as evidenced by propanol’s high market price per tonne (approximately US$ 1,400–1,600). However, CO electroreduction to n-propanol has shown low selectivity, limited production rates and poor stability. Here we report catalysts, identified using computational screen...

High-throughput characterization of electrochemical reactions can accelerate discovery and optimization cycles, and provide the data required for further acceleration via machine-learning guided experiment planning. There are a range of high...

Metal borides/borates have been considered promising as oxygen evolution reaction catalysts; however, to date, there is a dearth of evidence of long-term stability at practical current densities. Here we report a phase composition modulation approach to fabricate effective borides/borates-based catalysts. We find that metal borides in-situ formed m...

We explore the selective electrocatalytic hydrogenation of lignin monomers to methoxylated chemicals, of particular interest, when powered by renewable electricity. Prior studies, while advancing the field rapidly, have so far lacked the needed selectivity: when hydrogenating lignin-derived methoxylated monomers to methoxylated cyclohexanes, the de...

Perovskite quantum dots (QDs) are of interest for solution‐processed lasers; however, their short Auger lifetime has limited lasing operation principally to the femtosecond temporal regime the photoexcitation levels to achieve optical gain threshold are up to two orders of magnitude higher in the nanosecond regime than in the femtosecond. Here the...

Stable and affordable electrocatalysts are urgently needed to accelerate the transition from conventional fossil fuels to sustainable energy resources such as solar and wind. Over the last two decades, the electrocatalytic splitting of water, and carbon dioxide reduction to hydrocarbons have received great attention, however approximately 90% of th...

The electrochemical conversion of CO 2 to methane provides a means to store intermittent renewable electricity in the form of a carbon-neutral hydrocarbon fuel that benefits from an established global distribution network. The stability and selectivity of reported approaches reside below technoeconomic-related requirements. Membrane electrode assem...

Catalytic hydrogenation of bio-oil provides an avenue to produce renewable chemicals. To this end, electrocatalytic hydrogenation is especially interesting when powered using low-carbon electricity; however, it has to date lacked the needed selectivity: when hydrogenating bio-oil to oxygenated hydrocarbons, for example, it reduces the desired oxyge...

Plasmonic nanostructures have played a key role in extending the activity of photocatalysts to the visible light spectrum, preventing the electron-hole combination and providing with hot electrons to the photocatalysts, a crucial step towards efficient broadband photocatalysis. One plasmonic photocatalyst, Au/TiO 2 , is of a particular interest bec...

We report formate production via CO2 electroreduction at a Faradaic efficiency (FE) of 93% and a partial current density of 930 mA cm-2, an activity level of potential industrial interest based on prior techno-economic analyses. We devise a catalyst synthesized using InP colloidal quantum dots (CQDs): the capping ligand exchange introduces surface...

Electroreduction uses renewable energy to upgrade carbon dioxide to value-added chemicals and fuels. Renewable methane synthesized using such a route stands to be readily deployed using existing infrastructure for the distribution and utilization of natural gas. Here we design a suite of ligand-stabilized metal oxide clusters and find that these mo...

Colloidal quantum dots (CQDs) are promising materials for IR light detection due to their tunable bandgap and solution processing; but to date, the time response of CQD IR photodiodes has been inferior to that provided by Si and InGaAs. We reasoned that the high permittivity of II-VI CQDs leads to slow charge extraction due to screening and capacit...

The atmosphere contains an abundance of fresh water, but this resource has yet to be harvested efficiently. To date, passive atmospheric water sorbents have required a desorption step that relies on steady solar irradiation. Since the availability and intensity of solar radiation vary, these limit on-demand desorption and hence the amount of harves...

The oxygen evolution reaction (OER) limits electrocatalysis due to the high overpotential incurred by the poor reaction kinetics; this problem worsens over time if the performance of the OER electrocatalyst diminishes during operation. Here, we report the synthesis of immiscible Ni-Co-Se nanoparticles (<10 nm) for alkaline OER using milling at a cr...

Infrared‐absorbing colloidal quantum dots (IR CQDs) are materials of interest in tandem solar cells to augment perovskite and cSi photovoltaics (PV). Today's best IR CQD solar cells rely on the use of passivation strategies based on lead iodide; however, these fail to passivate the entire surface of IR CQDs. Lead chloride passivated CQDs show impro...

Due to the rapid increase in their efficiencies, third generation photovoltaics rose to prominence in recent years, and became serious competitors to conventional silicon based and thin film solar cells. This work investigates various techniques to grow and/or deposit copper oxide (CuO) on a copper substrate for utilization as a counter electrode i...

To develop operative surface-enhanced Raman spectroscopy (SERS) sensors, nanostructures with high signal enhancement and ease of production are highly desired. SERS-active nanoparticle-gap-film (NGF) sandwich substrate using graphene as the gap nanospacer is of particular interest due to its strong local field enhancement associated with the atomic...

The surface plasmon resonance of dewetted Au structures on TiO2 substrate using physical vapor deposition and post-annealing is investigated. In this work, we employ an aperture-probe scanning near-field optical microscope (SNOM) to study the plasmonic properties of dewetted Au structures and the influence of the size, shape, and interdistance of t...

Crude oil and the rock surface interactions are key inputs to develop innovative methods for enhanced oil recovery (EOR). In this work, a novel in-situ atomic force microscopy technique (PeakForce Force Volume) is used to map the adhesion forces between dead crude oil and carbonate rocks rich with natural Calcite and Dolomite minerals. The samples...

This work demonstrates the viability of direct fabrication utilizing a single (deposition/anneal) process for polycrystalline silicon germanium sub-micro particles. The process combines plasma chemical vapor deposition enhanced with inductively coupled radio frequency plasma at intermediate pressure and high temperature for deposition and rapid the...

The energy harvested from the sun is an everlasting source with minimal effect on the environment. However, due to the lack of reliability and consistency in supply, the harvested energy from the sun needs to be converted and stored into a more reliable and effective means of fuel that can be used on demand. One of the promising solar-powered techn...

The construction and testing of a modular, low pressure compressed air energy storage (CAES) system is presented. The low pressure assumption (5 bar max) facilitates the use of isentropic relations to describe the system behavior, and practically eliminates the need for heat removal considerations necessary in higher pressure systems to offset the...

This study investigates the performance of dye-sensitized solar cells constructed with a Fe-Cu metastable material as the mesoporous layer on which a natural organic dye is applied. The synthesis of the Fe-Cu material is done via a high throughput process that produces nanosized particles from elemental metallic powders. Xanthophyll is singled out...

This paper investigates the effect of applying static and dynamic magnetic fields on the deposition of Fe-Cu compound on the working electrode of a dye-sensitized solar cell. The deposition of this compound on glass is complicated due to the fact that it cannot be evaporated or sintered beyond the dissociation temperature of 973 K (700 °C), and the...

This paper investigates the effect of applying static and dynamic magnetic fields on the deposition of Fe-Cu compound on the working electrode of a dye-sensitized solar cell. The deposition of this compound on glass is complicated due to the fact that it cannot be evaporated sintered beyond the dissociation temperature of 973 K (700°C), and the doc...

Titanium dioxide (TiO2) loaded with gold (Au) as noble metal, acts as an efficient photocatalyst that has been extensively investigated for water splitting processes. In this paper, we report on the microstructure of atomic layer deposited titanium dioxide and the crystallinity modification of the material using energetic electron beam irradiation....

This paper investigates the synthesis, microstructural characterization, electrical and optical and thermal testing of Fe-Cu metastable alloy system for selective solar absorption applications. The system is produced by mechanical alloying (MA) using high energy ball milling while monitoring its crystallographic morphology via X-ray diffraction (XR...

This work evaluates the suitability of the Al 64 Cu 25 Fe 11 compound to enhance spectral solar absorption when replacing the mesoporous layer material of dye-sensitized solar cells. The compound is produced by high-energy ball milling, a mechanical alloying technique that ensures extensive inter-diffusion of the elemental components, while heat...

This paper investigates the synthesis, microstructural characterization and thermal and optical properties of Al-Cu-Fe quasicrystalline system for selective solar absorption applications. A nominal composition of was produced by mechanical alloying (MA) using high-energy ball milling. Subsequent annealing was performed on the quasicrystalline sampl...