Microenvironment Engineering of Single/Dual‐Atom Catalysts for Electrocatalytic Application

Advanced Materials, Journal Year: 2023, Volume and Issue: 35(31)

Published: Feb. 23, 2023

Single/dual-metal atoms supported on carbon matrix can be modulated by coordination structure and neighboring active sites. Precisely designing the geometric electronic uncovering structure-property relationships of single/dual-metal confront with grand challenges. Herein, this review summarizes latest progress in microenvironment engineering single/dual-atom sites via a comprehensive comparison single-atom catalyst (SACs) dual-atom catalysts (DACs) term design principles, modulation strategy, theoretical understanding structure-performance correlations. Subsequently, recent advances several typical electrocatalysis process are discussed to get general reaction mechanisms finely-tuned SACs DACs. Finally, full-scaled summaries challenges prospects given for This will provide new inspiration development atomically dispersed electrocatalytic application.

Language: Английский

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Promoting Oxygen Reduction Reaction on Atomically Dispersed Fe Sites via Establishing Hydrogen Bonding with the Neighboring P Atoms

Advanced Energy Materials, Journal Year: 2022, Volume and Issue: 13(5)

Published: Dec. 16, 2022

Abstract Single atom catalysts (SACs) comprised of nitrogen‐coordinated transition metal (TM–N–C) moieties show encouraging performance towards the oxygen reduction reaction (ORR). Nevertheless, for reactions involving multiple intermediates, single‐atom sites fail to satisfactorily optimize adsorption all intermediates. Here, a facile strategy is reported construct Fe, P dual‐atom in multimodal porous carbon (Fe,P‐DAS@MPC), and its superiority synergistically boosting ORR demonstrated. Fe,P‐DAS@MPC exhibits excellent with substantially positive onset potential ( E = 1.02 V) half‐wave 1/2 0.92 V). Theoretical analysis unveils cooperative effect composed adjacent Fe atoms, aiding hydrogen bonding interaction can promote adsorption/desorption Additionally, Zn–air battery based on shows high peak power density exceptional cycling stability. These findings provide novel avenue design electrocatalysts practical energy conversion applications.

Language: Английский

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Understanding the complexity in bridging thermal and electrocatalytic methanation of CO₂

Chemical Society Reviews, Journal Year: 2023, Volume and Issue: 52(11), P. 3627 - 3662

Published: Jan. 1, 2023

The selective methanation of CO2 is an important research area to meet the net-zero emission targets. Furthermore, it crucial develop solutions achieve carbon neutrality, hydrogen utilization, circularity, and chemical-energy storage. This conversion can be realized via thermocatalytic multistep power-to-X route or by direct electro- (or photoelectro)-catalytic technologies. Herein, we discuss need accelerate Improving these technologies requires a better understanding catalytic chemistry complexity aspects consider in bridging electrocatalytic methanation. In this tutorial review, initially analyze fundamental question competitive adsorption key reactants regulation strategies promote overall reaction. Then, approach used guide reader differences between thermocatalysis electrocatalysis. Finally, necessary include modelling designing next-generation electrocatalysts for analyzed.

Language: Английский

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Ligand-Bound CO₂ as a Nonclassical Route toward Efficient Photocatalytic CO₂ Reduction with a Ni N-Confused Porphyrin

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(15), P. 10550 - 10558

Published: April 8, 2024

Implementing the synergistic effects between metal and ligand has successfully streamlined energetics for CO2 activation gained high catalytic activities, establishing important breakthroughs in photocatalytic reduction. Herein, we describe a Ni(II) N-confused porphyrin complex (NiNCP) featuring an acidic N–H group. It is readily deprotonated exists anion form during catalysis. Owing to this functional site, NiNCP gave rise outstanding turnover number (TON) as 217,000 with 98% selectivity reduction CO, while parent (NiTPP) was found be nearly inactive. Our mechanistic analysis revealed nonclassical reaction pattern where effectively activated via attack of Lewis-basic ligand. The resulting ligand-bound adduct could further reduced produce CO. This new metal–ligand effect anticipated inspire design highly active catalysts small molecule activations.

Language: Английский

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Regulating the Electronic Configuration of Ni Sites by Breaking Symmetry of Ni‐Porphyrin to Facilitate CO₂ Photocatalytic Reduction

Advanced Functional Materials, Journal Year: 2024, Volume and Issue: 34(25)

Published: Feb. 10, 2024

Abstract Adapting the coordination environment to influence electronic configuration of active sites represents an efficient approach for improving photocatalytic performance CO 2 reduction reaction (CO RR) but how execute it precisely remains challenging. Herein, heteroatom‐substitution in Ni‐porphyrin break symmetry Ni center is proposed be effective solution. Based on this, two symmetry‐breaking Ni‐porphyrins, namely Ni(Cl)ON 3 Por and Ni(Cl)SN , are designed successfully prepared. By theoretical calculation, found that efficiently regulates d orbital energy levels center. Furthermore, experimental findings jointly revealed Ni‐porphyrins facilitates generation highly reactive I species during catalytic process, effectively stabilizing reducing barrier formation key * COOH intermediate. As a result, gave production rates 24.7 38.8 mmol g −1 h as well selectivity toward 94.0% 96.4%, respectively, outperforming symmetric NiN 4 rate 6.6 82.8%). These offer microscopic insights into modulate activity by tuning rational design competent catalyst RR photocatalysis.

Language: Английский

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Molecular Design Principles to Elongate the Metal-to-Ligand Charge Transfer Excited-State Lifetimes of Square-Planar Nickel(II) Complexes

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(48), P. 21948 - 21960

Published: Nov. 23, 2022

Square-planar NiII complexes and their electronically excited states play key roles in cross-coupling catalysis could offer new opportunities to complement well-known isoelectronic PtII luminophores. Metal-to-ligand charge transfer (MLCT) deactivation pathways are particularly relevant these contexts. We sought extend the lifetimes of 3MLCT square-planar by creating coordination environments that seemed well adapted 3d8 valence electron configuration. Using a rigid tridentate chelate ligand, which central cyclometalated phenyl unit is flanked two coordinating N-heterocyclic carbenes, along with monodentate isocyanide very strong ligand field created. Bulky substituents at backbone furthermore protect center from nucleophilic attack axial directions. UV-Vis transient absorption spectroscopies reveal upon excitation into 1MLCT bands ultrafast intersystem crossing state, latter relaxes onward metal-centered triplet state (3MC). A torsional motion NiII-carbon bond elongation facilitate relaxation 3MC state. The lifetime gets longer increasing strength improved steric protection, thereby revealing clear design guidelines for enhanced photophysical properties. longest reached solution room temperature 48 ps, factor 5-10 compared previously investigated complexes. Our study contributes making first-row transition metal partially filled d-orbitals more amenable applications photophysics photochemistry.

Language: Английский

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Multifunctional Charge and Hydrogen‐Bond Effects of Second‐Sphere Imidazolium Pendants Promote Capture and Electrochemical Reduction of CO₂in Water Catalyzed by Iron Porphyrins**

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(37)

Published: July 25, 2022

Microenvironments tailored by multifunctional secondary coordination sphere groups can enhance catalytic performance at primary metal active sites in natural systems. Here, we capture this biological concept synthetic systems developing a family of iron porphyrins decorated with imidazolium (im) pendants for the electrochemical CO2 reduction reaction (CO2 RR), which promotes multiple synergistic effects to RR and enables disentangling second-sphere contributions that stem from each type interaction. Fe-ortho-im(H), poises units featuring both positive charge hydrogen-bond capabilities proximal center, increases binding affinity 25-fold activity 2000-fold relative parent Fe tetraphenylporphyrin (Fe-TPP). Comparison monofunctional analogs reveals through-space have greater impact on compared hydrogen bonding context.

Language: Английский

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Role‐Specialized Division of Labor in CO₂Reduction with Doubly‐Functionalized Iron Porphyrin Atropisomers

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(35)

Published: July 5, 2022

Abstract In enzymes, the active site residues function differently to promote chemical reactions. Such a role‐specialized division of labor has been rarely realized by synthetic catalysts. We report herein on catalytic CO 2 reduction with Fe porphyrins decorated two cationic N,N,N ‐trimethylbenzylamine groups in cis ‐ or trans ‐arrangement. The ‐isomer outperforms and reaches TOF max 4.4×10 5 s −1 acetonitrile using phenol proton source. Theoretical studies revealed that units are more effective than single unit improve binding, importantly, they but cooperatively C−O bond cleavage: one interacts ‐adduct, while other molecule through electrostatic interactions. This work therefore presents significant example catalysts, which boost reactions strategy for substrate activation.

Language: Английский

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Rational Design of Metal–Organic Frameworks for Electroreduction of CO₂ to Hydrocarbons and Carbon Oxygenates

ACS Central Science, Journal Year: 2022, Volume and Issue: 8(11), P. 1506 - 1517

Published: Oct. 25, 2022

Since CO

Language: Английский

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Linear Free Energy Relationships and Transition State Analysis of CO₂ Reduction Catalysts Bearing Second Coordination Spheres with Tunable Acidity

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(31), P. 17176 - 17186

Published: July 27, 2023

In molecular catalysts, protic functional groups in the secondary coordination sphere (SCS) work conjunction with an exogenous acid to relay protons active site of electrochemical CO2 reduction; however, it is not well understood how acidity SCS and together determine kinetics catalytic turnover. To evaluate relative contributions proton transfer driving forces, we synthesized a series modular iron tetraphenylporphyrin electrocatalysts bearing amides tunable pKa (17.6 20.0 dimethyl sulfoxide (DMSO)) employed phenols variable (15.3 19.1) as acids. This system allowed us (1) from forces associated either or (2) obtain mechanistic insights into reduction function pKa. A linear free-energy relationships show that become increasingly sensitive variations when more acidic acids are used (0.82 ≥ Brønsted α 0.13), increased (0.62 0.32). An Eyring analysis suggests rate-determining transition state becomes ordered decreasing acidity, which consistent proposal modulates charge accumulation solvation at rate-limiting state. Together, these enable optimization activation barriers both can further guide rational design electrocatalytic systems wherein all participants considered.

Language: Английский

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