Publications by authors named "Rafia Ahmad"

Enhancing corrosion resistance is essential for developing efficient electrocatalysts for acidic oxygen evolution reaction (OER). Herein, we report the strategic manipulation of the local compressive strain to reinforce the anti-corrosion properties of the non-precious CoO support. The incorporation of Ru single atoms, larger in atomic size than Co, into the CoO lattice (Ru-CoO), triggers localized strain compression and lattice distortion on the Co-O lattice.

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The electrocatalytic synthesis of ammonia (NH) through the nitrogen reduction reaction (NRR) under ambient temperature and pressure is emerging as an alternative approach to the conventional Haber-Bosch process. However, it remains a significant challenge due to poor kinetics, low nitrogen (N) solubility in aqueous electrolytes, and the competing hydrogen evolution reaction (HER), which can significantly impact NH production rates and Faradaic efficiency (FE). Herein, a rationally designed boron-doped molybdenum sulfide (B-Mo-MoS) electrocatalyst is reported that effectively enhances N reduction to  NH with an onset potential of -0.

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Hydrogen sulfide is a significant byproduct of oil and gas production and is typically recovered as elemental sulfur, a low-value commodity. In recent years, there have been efforts to upgrade HS through elemental decomposition to S and H, an essential energy carrier in a sustainable economy. Among the promising approaches is thermocatalytic looping, which involves a sulfide-based redox pair.

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Our study unveils a pioneering methodology that effectively distributes Pd species within a zeolitic imidazolate framework-8 (ZIF-8). We demonstrate that Pd can be encapsulated within ZIF-8 as atomically dispersed Pd species that function as an excited-state transition metal catalyst for promoting carbon-carbon (C-C) cross-couplings at room temperature using visible light as the driving force. Furthermore, the same material can be reduced at 250 °C, forming Pd metal nanoparticles encapsulated in ZIF-8.

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Metal-organic frameworks have drawn attention as potential catalysts owing to their unique tunable surface chemistry and accessibility. However, their application in thermal catalysis has been limited because of their instability under harsh temperatures and pressures, such as the hydrogenation of CO to methanol. Herein, we use a controlled two-step method to synthesize finely dispersed Cu on a zeolitic imidazolate framework-8 (ZIF-8).

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Typically, transition metals are considered as the centers for the activation of dinitrogen. Here we demonstrate that the nitride hydride compound Ca CrN H, with robust ammonia synthesis activity, can activate dinitrogen through active sites where calcium provides the primary coordination environment. DFT calculations also reveal that an associative mechanism is favorable, distinct from the dissociative mechanism found in traditional Ru or Fe catalysts.

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The photoelectrochemical (PEC) approach is attractive as a promising route for the nitrogen reduction reaction (NRR) toward ammonia (NH ) synthesis. However, the challenges in synergistic management of optical, electrical, and catalytic properties have limited the efficiency of PEC NRR devices. Herein, to enhance light-harvesting, carrier separation/transport, and the catalytic reactions, a concept of decoupling light-harvesting and electrocatalysis by employing a cascade n np -Si photocathode is implemented.

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Introduction: The present study investigated the role of the Basolateral Amygdala (BLA) N-methyl-D-aspartate (NMDA) receptors in stress-induced spatial memory disturbance among the male Wistar rats.

Methods: The male Wistar rats (Average weight =200 g) were cannulated bilaterally in the BLA, and entered the study (n=6-8) after one week. They received seven electro-foot-shock stress sessions on seven consecutive days.

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We report here the first step by step anchoring of a W(≡CBu)(CHBu) complex on a highly crystalline and mesoporous MOF, namely Zr-NU-1000, using a Surface Organometallic Chemistry (SOMC) concept and methodology. SOMC allowed us to selectively graft the complex on the Zr clusters and characterize the obtained single site material using state of the art experimental methods including extensive solid-state NMR techniques and HAADF-STEM imaging. Further FT-IR spectroscopy revealed the presence of a W═O moiety arising from the in situ reaction of the W≡CBu functionality with the coordinated water coming from the 8-connected hexanuclear Zr clusters.

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The combination of well-defined molecular cavities and chemical functionality makes crystalline porous solids attractive for a great number of technological applications, from catalysis to gas separation. However, in contrast to other widely applied synthetic solids such as polymers, the lack of processability of crystalline extended solids hampers their application. In this work, we demonstrate that metal-organic frameworks, a type of highly crystalline porous solid, can be made solution processable via outer surface functionalization using N-heterocyclic carbene ligands.

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We report stable ultrathin Au nanowires supported on reduced graphene oxide with outstanding electrocatalytic activity for borohydride oxidation. Electrochemical impedance spectroscopy measurements showed abnormal inductive behavior, indicative of surface reactivation. DFT calculations indicate that the origin of the high activity stems from the position of the Au d-band center.

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