Metal–Organic Framework-Based Catalysts with Single Metal Sites

Chemical Reviews, Journal Year: 2020, Volume and Issue: 120(21), P. 12089 - 12174

Published: May 1, 2020

Metal-organic frameworks (MOFs) are a class of distinctive porous crystalline materials constructed by metal ions/clusters and organic linkers. Owing to their structural diversity, functional adjustability, high surface area, different types MOF-based single sites well exploited, including coordinately unsaturated from nodes metallolinkers, as active species immobilized MOFs. Furthermore, controllable thermal transformation MOFs can upgrade them nanomaterials functionalized with single-atom catalysts (SACs). These unique features derivatives enable serve highly versatile platform for catalysis, which has actually been becoming rapidly developing interdisciplinary research area. In this review, we overview the recent developments catalysis at in emphasis on structures applications thermocatalysis, electrocatalysis, photocatalysis. We also compare results summarize major insights gained works providing challenges prospects emerging field.

Language: Английский

---

Atomic-level insight into super-efficient electrocatalytic oxygen evolution on iron and vanadium co-doped nickel (oxy)hydroxide

Nature Communications, Journal Year: 2018, Volume and Issue: 9(1)

Published: July 17, 2018

It is of great importance to understand the origin high oxygen-evolving activity state-of-the-art multimetal oxides/(oxy)hydroxides at atomic level. Herein we report an evident improvement oxygen evolution reaction via incorporating iron and vanadium into nickel hydroxide lattices. X-ray photoelectron/absorption spectroscopies reveal synergistic interaction between iron/vanadium dopants in host matrix, which subtly modulates local coordination environments electronic structures iron/vanadium/nickel cations. Further, in-situ absorption spectroscopic analyses manifest contraction metal-oxygen bond lengths activated catalyst, with a short vanadium-oxygen distance. Density functional theory calculations indicate that site co-doped (oxy)hydroxide gives near-optimal binding energies intermediates has lower overpotential compared sites. These findings suggest doped distorted geometric disturbed makes crucial contribution trimetallic catalyst.

Language: Английский

---

Accelerated Hydrogen Evolution Kinetics on NiFe‐Layered Double Hydroxide Electrocatalysts by Tailoring Water Dissociation Active Sites

Advanced Materials, Journal Year: 2018, Volume and Issue: 30(10)

Published: Jan. 19, 2018

Abstract Owing to its earth abundance, low kinetic overpotential, and superior stability, NiFe‐layered double hydroxide (NiFe‐LDH) has emerged as a promising electrocatalyst for catalyzing water splitting, especially oxygen evolution reaction (OER), in alkaline solutions. Unfortunately, result of extremely sluggish dissociation kinetics (Volmer step), hydrogen (HER) activity the NiFe‐LDH is rather poor environment. Here novel strategy demonstrated substantially accelerating by partially substituting Fe atoms with Ru. In 1 m KOH solution, as‐synthesized Ru‐doped nanosheets (NiFeRu‐LDH) exhibit excellent HER performance an overpotential 29 mV at 10 mA cm −2 , which much lower than those noble metal Pt/C reported electrocatalysts. Both experimental theoretical results reveal that introduction Ru into can efficiently reduce energy barrier Volmer step, eventually kinetics. Benefitting from outstanding remained OER activity, NiFeRu‐LDH steadily drives electrolyzer current density cell voltage 1.52 V, values Pt/C–Ir/C couple state‐of‐the‐art overall water‐splitting

Language: Английский

---

Preparation of two dimensional layered double hydroxide nanosheets and their applications

Chemical Society Reviews, Journal Year: 2017, Volume and Issue: 46(19), P. 5950 - 5974

Published: Jan. 1, 2017

This review summarizes pathways to obtain LDH nanosheets for various applications, provides an overview of the current understanding mechanistic studies, and promotes a better fundamental chemistry, which will in turn be beneficial wider scientific community, present potential future directions research areas.

Language: Английский

---

Artificial photosynthesis: opportunities and challenges of molecular catalysts

Chemical Society Reviews, Journal Year: 2019, Volume and Issue: 48(7), P. 2216 - 2264

Published: Jan. 1, 2019

This review emphasizes the significance of molecular catalysts in artificial photosynthesis, and discusses opportunities, challenges future catalysis.

Language: Английский

---

Support and Interface Effects in Water‐Splitting Electrocatalysts

Advanced Materials, Journal Year: 2019, Volume and Issue: 31(31)

Published: March 6, 2019

Water-splitting electrolyzers that can convert electricity into storable hydrogen are a fascinating and scalable energy conversion technology for the utilization of renewable energies. To speed up sluggish oxygen evolution reactions (HER OER), electrocatalysts essential reducing their kinetic barriers eventually improving efficiency. As efficient strategies modulating binding ability water-splitting intermediates on electrocatalyst surface, support effect interface drawing growing attention. Herein, some recent research progress effects in HER, OER, overall is highlighted. Specifically, correlation between electronic interaction constituent components electrocatalytic performance profoundly discussed, with aim advancing development highly electrocatalysts, which may replace noble-metal-based bring practically widespread reality.

Language: Английский

---

Recent advances in activating surface reconstruction for the high-efficiency oxygen evolution reaction

Chemical Society Reviews, Journal Year: 2021, Volume and Issue: 50(15), P. 8428 - 8469

Published: Jan. 1, 2021

The recent progress in activating surface reconstruction by integrating advanced characterizations with theoretical calculations for high-efficiency oxygen evolution reaction is reviewed.

Language: Английский

---

Single Atoms and Clusters Based Nanomaterials for Hydrogen Evolution, Oxygen Evolution Reactions, and Full Water Splitting

Advanced Energy Materials, Journal Year: 2019, Volume and Issue: 9(22)

Published: May 2, 2019

Abstract The sustainable and scalable production of hydrogen through evolution reaction (HER) oxygen (OER) in water splitting demands efficient robust electrocatalysts. Currently, state‐of‐the‐art electrocatalysts Pt IrO 2 /RuO exhibit the benchmark catalytic activity toward HER OER, respectively. However, expanding their practical application is hindered by exorbitant price scarcity. Therefore, development alternative effective for crucial. In last few decades, substantial effort has been devoted to HER/OER catalysts based on various transition metals (including Fe, Co, Ni, Mo, atomic Pt) which show promising activities durability. this review, after a brief introduction basic mechanism HER/OER, authors systematically discuss recent progress design, synthesis, single atom cluster‐based catalysts. Moreover, crucial factors that can tune such as morphology, crystal defects, hybridization with nonmetals, heteroatom doping, alloying, formation inside graphitic layered materials are discussed. Finally, existing challenges future perspectives improving performance addressed.

Language: Английский

---

Mechanism of Oxygen Evolution Catalyzed by Cobalt Oxyhydroxide: Cobalt Superoxide Species as a Key Intermediate and Dioxygen Release as a Rate-Determining Step

Journal of the American Chemical Society, Journal Year: 2020, Volume and Issue: 142(27), P. 11901 - 11914

Published: June 15, 2020

The oxygen evolution reaction (OER) is the performance-limiting half of water splitting, which can be used to produce hydrogen fuel using renewable energies. Whereas a number transition metal oxides and oxyhydroxides have been developed as promising OER catalysts in alkaline medium, mechanisms on these are not well understood. Here we combine electrochemical situ spectroscopic methods, particularly operando X-ray absorption Raman spectroscopy, study mechanism cobalt oxyhydroxide (CoOOH), an archetypical unary catalyst. We find dominating resting state catalyst Co(IV) species CoO2. Through isotope exchange experiments, discover superoxide active intermediate OER. This formed concurrently oxidation CoOOH Combing electrokinetic data, identify rate-determining step release dioxygen from intermediate. work provides important experimental fingerprints new mechanistic perspectives for catalysts.

Language: Английский

---

Reactive Fe-Sites in Ni/Fe (Oxy)hydroxide Are Responsible for Exceptional Oxygen Electrocatalysis Activity

Journal of the American Chemical Society, Journal Year: 2017, Volume and Issue: 139(33), P. 11361 - 11364

Published: Aug. 9, 2017

Fe is a critical component of record-activity Ni/Fe (oxy)hydroxide (Ni(Fe)OxHy) oxygen evolution reaction (OER) catalysts, yet its precise role remains unclear. We report evidence for different types species within Ni(Fe)OxHy- those that are rapidly incorporated into the Ni oxyhydroxide from cations in solution (and likely at edges or defects) and responsible enhanced OER activity, substituting bulk modulate observed voltammetry. These results suggest exceptional activity Ni(Fe)OxHy does not depend on average electrochemical properties measured by voltammetry, instead emphasize local structure.

Language: Английский

---