Exsolved metal-boosted active perovskite oxide catalyst for stable water gas shift reaction

Huang, Rui; Lim, Chaesung; Jang, Myeong Gon; Hwang, Ji Young; Han, Jeong Woo

doi:10.1016/j.jcat.2021.05.029

Cited by 25 publications

(22 citation statements)

References 76 publications

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“…The WGSR was further mechanistically studied using DFT calculations to show how each surface atom control method influences the WGSR reactivity. Defining a WGSR pathway before a mechanistic study can be efficient because many pathways, such as associative and redox pathways, have been known to be possible. , Among the associative pathways, which include carbon-containing intermediates such as carboxyl and formate species, carboxyl pathway has been reported to be dominant on oxide-supported metal systems in many studies. , In particular, Song and Hensen argued that the carboxyl pathway is strongly preferred over the redox pathway for the WGSR on CeO 2 -supported Au nanorods . Aranifard et al showed that the WGSR on another CeO 2 -supported system of Pt/CeO 2 follows the carboxyl path .…”

Section: Resultsmentioning

confidence: 99%

Boosting Support Reducibility and Metal Dispersion by Exposed Surface Atom Control for Highly Active Supported Metal Catalysts

et al. 2022

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For oxide-supported metal catalysts, support reducibility and metal dispersion are the key factors to determine the activity and selectivity in many essential reactions involving redox process. Herein, we tuned the exposed surface atoms of the catalyst by facet control and doping methods, which were simultaneously applied to boost the reducibility and metal dispersion of an oxide support. Pd supported on Cu-doped CeO2 (Pd/CDC) for water–gas shift reaction (WGSR) was considered a model system; Cu was doped into the cubic and octahedral CeO2 enclosed with (100) and (111) facets, respectively. By a systematic combination of density functional theory calculations and experimental analyses, the WGSR activity of the Pd/CDC cube was verified to synergistically increase by more than just the sum of the morphology and Cu doping effects. The effect of each tuning method on the activity was further investigated from a mechanistic perspective. This work presents a rational design knowledge to enhance the catalytic activity that can be extended to a wide range of supported metal systems.

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Section: Resultsmentioning

confidence: 99%

Boosting Support Reducibility and Metal Dispersion by Exposed Surface Atom Control for Highly Active Supported Metal Catalysts

et al. 2022

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“…This method has been proven to be efficient in predicting the trend of H 2 O dissociation ability for WGSR catalysts. 15 The results showed that H 2 O dissociation occurs at a higher temperature (145 °C) on the unsupported Pd sample than on the C200 sample with the interface (91 °C), indicating that the thermal energy required to dissociate H 2 O (or the E a ) was reduced by the interface, validating the promotion of the H 2 O dissociation by the Pd/Co 3 O 4 interface.…”

Section: ■ Results and Discussionmentioning

confidence: 77%

“…The deuterium oxide (D 2 O)−H 2 exchange reaction was performed using the BELCAT II catalyst analyzer (Micro-tracBEL, Corp.). 15 First, to eliminate impurities before the tests, 30 mg of the catalyst was transferred to a quartz tube and pretreated at 150 °C for 30 min under Ar conditions (50 sccm). Thereafter, 80 mL of D 2 O (Sigma-Aldrich, 99.9 at.…”

Section: ■ Conclusionmentioning

confidence: 99%

Role of an Interface for Hydrogen Production Reaction over Size-Controlled Supported Metal Catalysts

et al. 2022

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The water–gas shift reaction (WGSR) is important in industries because it can reduce the CO content of syngas to produce purified H2, which can be used as fuel or to make ammonia (NH3). Supported noble metal catalysts have been widely studied for the WGSR because they exhibit high reactivity. However, the role of a metal–support interface in the WGSR has not yet been revealed and remains elusive. Density functional theory (DFT) calculations were performed for a model system of Co3O4-supported Pd (Pd/Co3O4) catalysts. The presence of the interface was found to promote the H2O dissociation step, which is crucial for improving WGSR activity. Thus, the WGSR activity was predicted to be enhanced by an increased number of interfaces, which could be achieved by controlling the size of the supported Pd nanoparticles (NPs). Furthermore, electronic metal–support interactions (MSIs) were found to be a source of the promoted H2O dissociation at the interface. The DFT-predicted promotion of H2O dissociation was further experimentally validated using Pd/Co3O4 catalysts that were size-controlled with calcination temperatures, and the total length of the interface was shown to have a direct correlation with the WGSR rate. Theoretical insights into the role of the interface and the enhancement of WGSR activity due to increased interface sites, which can be achieved by size control, are believed to be useful in the design of efficient supported metal catalysts for the WGSR.

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“…64 To address this issue, WGSR can be applied as a downstream process (eqn (1)) where CO is converted to CO 2 and H 2 , thus removing carbon monoxide from syngas to obtain high-purity hydrogen and alleviating the release of toxic gases into the atmospheres. 65–76 Considering the exothermic nature, lower temperatures are conducive to higher carbon monoxide conversion; however, high temperatures will increase the reaction rate. Therefore, in commercial applications, the process is carried out in two steps (high-temperature reaction followed by low-temperature conversion) to achieve the purity level required for various industrial applications.…”

Section: Introductionmentioning

confidence: 99%

Modification strategies of heterogeneous catalysts for water–gas shift reactions

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Exsolved metal-boosted active perovskite oxide catalyst for stable water gas shift reaction

Cited by 25 publications

References 76 publications

Boosting Support Reducibility and Metal Dispersion by Exposed Surface Atom Control for Highly Active Supported Metal Catalysts

Boosting Support Reducibility and Metal Dispersion by Exposed Surface Atom Control for Highly Active Supported Metal Catalysts

Role of an Interface for Hydrogen Production Reaction over Size-Controlled Supported Metal Catalysts

Modification strategies of heterogeneous catalysts for water–gas shift reactions

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