Photoelectrocatalytic reduction of CO2 to formate using immobilized molecular manganese catalysts on oxidized porous silicon

Chem, Journal Year: 2025, Volume and Issue: unknown, P. 102462 - 102462

Published: March 1, 2025

Language: Английский

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Photoelectrochemical Proton-Coupled Electron Transfer of TiO₂ Thin Films on Silicon

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(15), P. 10559 - 10572

Published: April 2, 2024

TiO2 thin films are often used as protective layers on semiconductors for applications in photovoltaics, molecule–semiconductor hybrid photoelectrodes, and more. Experiments reported here show that silicon electrochemically photoelectrochemically reduced buffered acetonitrile at potentials relevant to photoelectrocatalysis of CO2 reduction, N2 H2 evolution. On both n-type Si irradiated p-type Si, reduction is proton-coupled with a 1e–:1H+ stoichiometry, demonstrated by the Nernstian dependence Ti4+/3+ E1/2 buffer pKa. were conducted without illumination, photovoltage ∼0.6 V was observed across 20 orders magnitude proton activity. The 4 nm almost stoichiometrically under mild conditions. catalytically transfer protons electrons hydrogen atom acceptors, based cyclic voltammogram, bulk electrolysis, other mechanistic evidence. TiO2/Si thus has potential generate high-energy H carriers. Characterization after reveals restructuring formation islands, rendering potentially poor choice protecting or catalyst supports reducing protic Overall, this work demonstrates atomic layer deposition photoelectrodes undergo chemical morphological changes upon application only modestly negative RHE these media. While results should serve cautionary tale researchers aiming immobilize molecular monolayers "protective" metal oxides, robust electron reactivity introduces opportunities photoelectrochemical generation reactive charge-carrying mediators.

Language: Английский

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Photoelectrochemical CO₂ Reduction to CO Enabled by a Molecular Catalyst Attached to High-Surface-Area Porous Silicon

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(12), P. 7998 - 8004

Published: March 15, 2024

A high-surface-area p-type porous Si photocathode containing a covalently immobilized molecular Re catalyst is highly selective for the photoelectrochemical conversion of CO2 to CO. It gives Faradaic efficiencies up 90% CO at potentials −1.7 V (versus ferrocenium/ferrocene) under 1 sun illumination in an acetonitrile solution phenol. The photovoltage approximately 300 mV based on comparisons with similar n-type cathodes dark. Using estimate equilibrium potential reduction optimized reaction conditions, photoelectrolysis was performed small overpotential, and onset electrocatalysis cyclic voltammograms occurred modest underpotential. photoelectrode more stable production than generated by attaching same planar wafer. Further, facile characterization Si-based photoelectrodes using transmission mode FTIR spectroscopy leads reproducible catalytic performance.

Language: Английский

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Synthesis and Surface Attachment of Molecular Re(I) Hydride Species with Silatrane Functionalized Bipyridyl Ligands

Organometallics, Journal Year: 2023, Volume and Issue: 42(16), P. 2238 - 2250

Published: Aug. 16, 2023

Three molecular Re hydrides of the form (Rbpy)Re(CO)3H with 2,2′-bipyridine (bpy) ligands containing silatrane functional groups for surface attachment on metal oxide surfaces were synthesized. IR spectroscopy and cyclic voltammetry (CV) demonstrated that complexes have electronic properties similar to those a control compound, which did not contain attachment. Additionally, in fashion are electrocatalysts reduction CO2 CO solution. The immobilized thin layer TiO2 Si, resulting composites characterized using X-ray photoelectron as well dark under illumination. Control experiments indicated hydride stable degrade species bpy ligand, three ligands, an unknown ligand sixth site. Similarly, when one was Si nanoparticles SiO2 or silica nanoparticles, lost. Density theory calculations used corroborate observed behavior surface. Overall, this work demonstrates difficulties associated attaching well-defined surfaces.

Language: Английский

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Direct Detection of Key Intermediates during the Product Release in Rhenium Bipyridine-Catalyzed CO₂ Reduction Reaction

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(21), P. 16324 - 16334

Published: Oct. 22, 2024

Rhenium bipyridine tricarbonyl complexes, fac-[Re(bpy)(CO)3X]n+, are highly effective in selectively converting CO2 to CO under electrochemical and photochemical conditions. Despite numerous mechanistic studies aimed at understanding its reduction reaction (CO2RR) pathway, the intermediates further into catalytic cycle have escaped detection, steps leading product release remained elusive. In this study, employing stopped-flow mixing coupled with time-resolved infrared spectroscopy, we observed, for first time, reduced Re-tetracarbonyl species, [Re(bpy)(CO)4]0, a half-life of approximately 55 ms acetonitrile solvent. This intermediate is proposed be common both CO2RR. Furthermore, directly observed (CO) from intermediate. Additionally, detected accumulation [Re(bpy)(CO)3(CH3CN)]+ as byproduct following release, significant side conditions limited supply reducing equivalents mirroring The process could unambiguously attributed an electron transfer-catalyzed ligand substitution involving [Re(bpy)(CO)4]0 by simultaneous real-time detection all involved species. We believe that significantly impacts CO2RR efficiency class catalysts or during electrocatalysis mild overpotentials.

Language: Английский

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Recent Advances in Immobilizing and Benchmarking Molecular Catalysts for Artificial Photosynthesis

Langmuir, Journal Year: 2024, Volume and Issue: 40(46), P. 24195 - 24215

Published: Nov. 4, 2024

Transition metal complexes have been widely used as catalysts or chromophores in artificial photosynthesis. Traditionally, they are employed homogeneous settings. Despite their functional versatility and structural tunability, broad industrial applications of these impeded by the limitations catalysis such poor catalyst recyclability, solvent constraints (mostly organic solvents), durability. Over past few decades, researchers developed various methods for molecular heterogenization to overcome limitations. In this review, we summarize recent developments strategies, with a focus on describing process effects catalytic performances. Alongside in-depth discussion review aims provide concise overview key metrics associated heterogenized systems. We hope will aid who new research field gaining better understanding.

Language: Английский

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Linear Free Energy Relationships Associated with Hydride Transfer From [(6,6′-R₂-bpy)Re(CO)₃H]: A Cautionary Tale in Identifying Hydrogen Bonding Effects in the Secondary Coordination Sphere

Inorganic Chemistry, Journal Year: 2024, Volume and Issue: 63(41), P. 19396 - 19407

Published: Sept. 30, 2024

Six rhenium hydride complexes, [(6,6'-R

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Statistical Analysis of HAADF-STEM Images to Determine the Surface Coverage and Distribution of Immobilized Molecular Complexes

Published: May 2, 2024

The surface immobilization of molecular catalysts is attractive because it combines the benefits homogeneous and heterogeneous catalysis. However, determining coverage distribution a catalyst on solid support often challenging, inhibiting our ability to design improved catalytic systems. Here, we demonstrate that combination scanning transmission electron microscopy (STEM) image analysis individual positions heavy atoms in transition metal complexes via convolutional neural network (CNN) allows statistically robust determination immobilized catalysts. These observations provide information about how changes functionalization conditions, attachment group, structure affect distribution, providing insight into chemical mechanism immobilization. method could be generally valuable for correlating activity, selectivity, stability system.

Language: Английский

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Well-defined surface catalytic sites for solar CO₂reduction: heterogenized molecular catalysts and single atom catalysts

Chemical Communications, Journal Year: 2023, Volume and Issue: 59(61), P. 9301 - 9319

Published: Jan. 1, 2023

New photocatalysts can be prepared via heterogenization of molecular complexes and creation atomically dispersed sites on surfaces. Structural investigation such surface catalytic requires extensive use spectroscopic techniques.

Language: Английский

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Heterogenous CO₂ Reduction Photocatalysis of Transparent Coordination Polymer Glass Membranes Containing Metalloporphyrins

Inorganic Chemistry, Journal Year: 2023, Volume and Issue: 62(29), P. 11342 - 11349

Published: July 11, 2023

Transparent and grain boundary-free substrates are essential to immobilize molecular photocatalysts for efficient photoirradiation reactions without unexpected light scattering absorption by the substrates. Herein, membranes of coordination polymer glass immobilizing metalloporphyrins were examined as a heterogeneous photocatalyst carbon dioxide (CO2) reduction under visible-light irradiation. [Zn(HPO4)(H2PO4)2](ImH2)2 (Im = imidazolate) liquid containing iron(III) 5,10,15,20-tetraphenyl-21H,23H-porphine chloride (Fe(TPP)Cl, 0.1-0.5 w/w%) was cast on borosilicate substrate, followed cooling room temperature, resulting in transparent with thicknesses 3, 5, 9 μm. The photocatalytic activity proportion membrane thickness, indicating that Fe(TPP)Cl subsurface effectively absorbed contributed reactions. intact during reaction showed no recrystallization or leaching Fe(TPP)Cl.

Language: Английский

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