Carboxyl intermediate formation via an in situ-generated metastable active site during water-gas shift catalysis

@article{Nelson2019CarboxylIF,
  title={Carboxyl intermediate formation via an in situ-generated metastable active site during water-gas shift catalysis},
  author={Nicholas C. Nelson and Manh‐Thuong Nguyen and Vassiliki‐Alexandra Glezakou and Roger Rousseau and J{\'a}nos Szanyi},
  journal={Nature Catalysis},
  year={2019},
  pages={1-9}
}
Definitive experimental proof for catalytic pathways and active sites during the low-temperature water-gas shift reaction remains elusive. Herein, we combine spectroscopic, kinetic and computational analyses to address the decades-long mechanistic controversy by studying the reverse water-gas shift over Pd/Al2O3. Isotopic transient kinetic analysis established the minor role of the formate intermediate, whereas hydrogen titration experiments confirmed the intermediacy of carboxyl. The ability… 
29 Citations
In Situ Dispersion of Pd on TiO2 During Reverse Water-Gas Shift Reaction: Formation of Atomically Dispersed Pd.
TLDR
It is shown that Pd can be predominantly dispersed as isolated atoms onto TiO 2 during the reverse water-gas shift (rWGS) reaction at 400 °C.
Site-Selective CO2 Reduction over Highly Dispersed Ru-SnOx Sites Derived from a [Ru@Sn9]6– Zintl Cluster
Due to the unstable nature of isolated transition metals under real reaction condition, a systematic understanding on how much influence the isolated structure of the active site and the cofed
Unlocking the Catalytic Potential of TiO2-Supported Pt Single Atoms for the Reverse Water–Gas Shift Reaction by Altering Their Chemical Environment
TLDR
A reduction–oxidation cycle that induces nearly 5-fold activity enhancement on Pt/TiO2 SACs for the reverse water–gas shift (rWGS) reaction is reported, offering desired understanding on the rarely explored dynamic chemical environment of supported single metal atoms and its catalytic consequences.
In Situ Raman Observation of Oxygen Activation and Reaction at Platinum-Ceria Interfaces during CO Oxidation.
TLDR
In situ SERS studies and density functional theory simulations reveal a more efficient molecular pathway through the reaction between adsorbed CO and chemisorbed Pt-O species transferred from the interfaces, leading to a much higher activity at platinum-ceria interfaces compared to that at Pt alone.
Ligand-coordinated Ir single-atom catalysts stabilized on oxide supports for ethylene hydrogenation and their evolution under a reductive atmosphere
In this work, we present a novel series of oxide-supported Ir-ligand single-atom catalysts (SACs) for ethylene hydrogenation. The SACs were created by a metal–ligand self-assembly strategy developed
The concept of active site in heterogeneous catalysis
Catalysis is at the core of chemistry and has been essential to make all the goods surrounding us, including fuels, coatings, plastics and other functional materials. In the near future, catalysis
Copper-zirconia interfaces in UiO-66 enable selective catalytic hydrogenation of CO2 to methanol
TLDR
It is shown that the direct link between the two phases (and not merely being together) is required to selectively hydrogenate CO2 to methanol on catalysts containing Cu and ZrO2.
...
1
2
3
...

References

SHOWING 1-10 OF 78 REFERENCES
Optimizing Binding Energies of Key Intermediates for CO2 Hydrogenation to Methanol over Oxide-Supported Copper.
TLDR
The importance of synergy between theory and experiments to elucidate the complex reaction mechanisms of CO2 hydrogenation for the realization of a better catalyst by design is demonstrated.
Elucidating the Role of Support Oxygen in the Water–Gas Shift Reaction over Ceria-Supported Gold Catalysts Using Operando Spectroscopy
Supported-metal (Au, Pt) ceria-based catalysts are considered as promising candidates for the water–gas shift (WGS) reaction at low temperatures. Two main mechanisms have been proposed in the
Importance of the metal-oxide interface in catalysis: in situ studies of the water-gas shift reaction by ambient-pressure X-ray photoelectron spectroscopy.
TLDR
It is shown herein how sites associated with a metal–ceria interface can dramatically change the reaction mechanism of the water–gas shift reaction (WGSR; CO + H2O!H2 + CO2).
Unravelling the Role of Oxygen Vacancies in the Mechanism of the Reverse Water–Gas Shift Reaction by Operando DRIFTS and Ultraviolet–Visible Spectroscopy
The reaction mechanism of the reverse water–gas shift (RWGS) reaction was investigated using two commercial gold-based catalysts supported on Al2O3 and TiO2. The surface species formed during the
On the Importance of the Associative Carboxyl Mechanism for the Water-Gas Shift Reaction at Pt/CeO2 Interface Sites
Periodic density functional theory calculations and microkinetic modeling are used to investigate the associative carboxyl pathways of the water-gas shift (WGS) reaction at the Pt/CeO2 (111)
In Situ Control of the Adsorption Species in CO2 Hydrogenation: Determination of Intermediates and Byproducts
CO2 hydrogenation over catalysts is a potentially exciting method to produce fuels while closing the CO2 cycle and mitigating global warming. The mechanism of this process has been controversial due
Dynamic formation of single-atom catalytic active sites on ceria-supported gold nanoparticles
TLDR
This study presents ab initio molecular dynamics simulations of an unprecedented dynamic single-atom catalytic mechanism for the oxidation of carbon monoxide by ceria-supported gold clusters and highlights the importance of the dynamic creation of active sites under reaction conditions and their essential role in catalysis.
Insights into Interfacial Synergistic Catalysis over Ni@TiO2- x Catalyst toward Water-Gas Shift Reaction.
TLDR
A combination study including in situ and operando EXAFS, in situ DRIFTS spectra combined with TPSR measurements substantiates a new redox mechanism based on interfacial synergistic catalysis, which is constructive for the rational design and fabrication of high activity heterogeneous catalysts.
A common single-site Pt(II)-O(OH)x- species stabilized by sodium on "active" and "inert" supports catalyzes the water-gas shift reaction.
TLDR
It is reported that catalytically similar single-atom-centric Pt sites are formed by binding to sodium ions through -O ligands, the ensemble being equally effective on supports as diverse as TiO2, L-zeolites, and mesoporous silica MCM-41.
...
1
2
3
4
5
...