Publications by authors named "R Crabtree"
The electrocatalytic aqueous ammonia oxidation (AO) represents a more sustainable alternative to accessing nitrite (NO) and nitrate (NO). We now report that Cu(pyalk) {pyalk = 2-(pyridin-2-yl)propan-2-oate}, previously employed as a homogeneous water oxidation (WO) catalyst, is also active for selective AO in aqueous environments. The traditional Griess analytical test for NO/NO was modified to permit the operation in the presence of the otherwise interfering Cu ion.
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- The study focuses on using transition metals, specifically rhenium, to split nitrogen (N) and form metal nitride complexes, which could lead to efficient electrochemical nitrogen fixation to create ammonia under mild conditions.
- The proposed nitrogen fixation cycle involves binding N to form a complex, cleaving the N bridge, and then undergoing proton/electron transfer to produce ammonia, while a catalyst must fulfill specific electronic requirements during these processes.
- The introduction of an isocyanide ligand in the rhenium system helps facilitate electron reduction and protonation, increasing the stability of the process and enabling ammonia production, demonstrating how modifying supporting ligands can improve reactivity in synthetic cycles for nitrogen conversion.
Synthesis-induced defects in single-walled carbon nanotubes (SWCNTs) enable diverse catalytic reactions, but the nature of catalytic intermediates and how active species regeneration occurs are unclear. Using a quantum mechanics/molecular mechanics (QM/MM) hybrid methodology based on density functional theory (DFT) and a classical force-field, we explore the reactivity and electrochemical regeneration of a vacancy defect in a zigzag SWCNT. Our findings indicate that hydrolysis of the defect forms a ketone group on one carbon atom and C-H bonds on two adjacent carbons.
View Article and Find Full Text PDFBackground: Emergency medical services (EMS) are often patients' first point of contact for urgent and emergency care needs. Patients are triaged over the phone and may receive an ambulance response, with potential conveyance to the hospital. A recent scoping review suggested disparities in EMS patient care in the United States.
View Article and Find Full Text PDFAdvancement toward dye-sensitized photoelectrochemical cells to produce solar fuels by solar-driven water splitting requires a photosensitizer that is firmly attached to the semiconducting photoelectrodes. Covalent binding enhances the efficiency of electron injection from the photoexcited dye into the metal oxide. Optimization of charge transfer, efficient electron injection, and minimal electron-hole recombination are mandatory for achieving high efficiencies.
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