Controlling the Oxidation State of Pt Single Atoms for Maximizing Catalytic Activity

Jeong, Hojin; Shin, Dongjae; Kim, Beom-Sik; Bae, Junemin; Shin, Sangyong; Choe, Changyeong; Han, Jeong Woo; Lee, Hyunjoo

doi:10.1002/anie.202009776

Cited by 149 publications

(105 citation statements)

References 44 publications

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“…Combination with the catalytic performance in Fig. 3a and previous reported 31 , 39 , the lower oxidized state of Pt species is appropriate for lower temperature CO oxidation. XANES data in Fig.…”

Section: Resultssupporting

confidence: 78%

“…When the catalysts were pretreated at 300 °C under air, Bi-free and Bi-promoted samples show almost same CO oxidation activity with complete CO conversion at ~220 °C (Supplementary Fig. 8 ), may due to poor ability to adsorb CO or overhigh valence of platinum species 31 . However, we found that hydrogen reduction significantly enhanced CO oxidation activity for Bi-promoted catalysts (Fig.…”

Section: Resultsmentioning

confidence: 99%

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Unique structure of active platinum-bismuth site for oxidation of carbon monoxide

Nan

et al. 2021

Nat Commun

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As the technology development, the future advanced combustion engines must be designed to perform at a low temperature. Thus, it is a great challenge to synthesize high active and stable catalysts to resolve exhaust below 100 °C. Here, we report that bismuth as a dopant is added to form platinum-bismuth cluster on silica for CO oxidation. The highly reducible oxygen species provided by surface metal-oxide (M-O) interface could be activated by CO at low temperature (~50 °C) with a high CO2 production rate of 487 μmolCO2·gPt−1·s−1 at 110 °C. Experiment data combined with density functional calculation (DFT) results demonstrate that Pt cluster with surface Pt−O−Bi structure is the active site for CO oxidation via providing moderate CO adsorption and activating CO molecules with electron transformation between platinum atom and carbon monoxide. These findings provide a unique and general approach towards design of potential excellent performance catalysts for redox reaction.

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Section: Resultssupporting

confidence: 78%

Section: Resultsmentioning

confidence: 99%

Unique structure of active platinum-bismuth site for oxidation of carbon monoxide

Nan

et al. 2021

Nat Commun

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show abstract

“…When the catalysts were pretreated at 300 °C under air, Bi-free and Bi-promoted samples shows almost same CO oxidation activity with complete CO conversion at ~ 220 °C ( Supplementary Fig. 8), may due to poor ability to adsorb CO or overhigh valence of platinum species 24 . However, we found that hydrogen reduction signi cantly enhanced CO oxidation activity for Bipromoted catalysts (Fig.…”

Section: Resultsmentioning

confidence: 99%

“…XANES data inFig. 4findicated platinum species are at low valence state after CO oxidation:Supplementary Table 2) due to hydrogen reduction, indicating lower oxidized state of Pt species are appropriate for lower temperature CO oxidation24,28 . In order to require more reliable local coordination structure for used Bi-promoted samples, we conducted the EXAFS tting process with or without Pt−O−Bi shell inSupplementary Fig.…”

mentioning

confidence: 99%

Novel structure of active platinum-bismuth site for oxidation of carbon monoxide

Nan

Miao

et al. 2020

Preprint

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As the technology development, the future advanced combustion engines must be designed to perform at a low temperature. Thus, it is a great challenge to synthesize high active and stable catalysts to resolve exhaust below 100 °C. Here, we report that bismuth as a dopant added to form platinum-bismuth cluster on silica for CO oxidation. The highly reducible oxygen species provided by surface metal-oxide (M-O) interface could be activated by CO at low temperature (~ 50 °C) with a high CO2 production rate of 487 µmolCO2·gPt−1·s− 1 at 110 °C. Experiment data combined with density functional calculation (DFT) results demonstrate that Pt cluster with surface Pt−O−Bi structure is the active site for CO oxidation via providing moderate CO adsorption and activating CO molecules with electron transformation between platinum atom and carbon monoxide. These findings provide a novel and general approach towards design of potential outstanding performance catalysts for redox reaction.

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“…[99] Catalysts containing 1 wt% platinum were prepared on highly defective cerium oxide particles supported on alumina and shown by EXAFS spectra, IR spectra of adsorbed CO, and STEM images to incorporate atomically dispersed platinum. [26] The samples were reduced at various temperatures in 10% H 2 /N 2 , and XANES and XPS data showed that the platinum oxidation state decreased as the reduction temperature increased, with atomic dispersion being retained even at 300 °C for the entrapped platinum atoms-and the data suggested that the formal oxidation state was close to zero. The catalysts were tested for CO oxidation, methane combustion, and NO oxidation, with the sample reduced at 300 °C showing the highest degree of reduction of the platinum and the highest activity for each reaction.…”

Section: Catalysis By Atomically Dispersed Supported Platinummentioning

confidence: 96%

Prototype Atomically Dispersed Supported Metal Catalysts: Iridium and Platinum

Chen

Sun

Gates

2020

Small

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Heterogeneous catalysis is the central enabling technology of fossil fuel conversion, chemical production, and vehicular and power plant emissions clean-up. Many of the catalysts are precious metals finely dispersed on porous high-area supports, such as metal oxides, zeolites, and carbon. The metals are usually present as zerovalent nanoparticles, and when the particles are made When metal nanoparticles on supports are made smaller and smaller-to the limit of atomic dispersion-they become cationic and take on new catalytic properties that are only recently being discovered. The synthesis of these materials is reviewed, including their structure characterization-especially by atomic-resolution electron microscopy and X-ray absorption and infrared spectroscopies-and relationships between structure and catalyst performance, for reactions including hydrogenations, oxidations, and the water gas shift. Structure determination is challenging because of the intrinsic nonuniformity of the support surfaces-and therefore the structures on them-but fundamental understanding has advanced rapidly, benefiting from nearly uniform catalysts consisting of metals on well-defined-crystalline-supports and their characterization by spectroscopy and microscopy. Recent advances in atomic-resolution electron microscopy have spurred the field, providing stunning images and deep insights into structure. The iridium catalysts have typically been made from organoiridium precursors, opening the way to understanding and control of the metal-support bonding and ligands on the metal, including catalytic reaction intermediates. Platinum catalysts are usually made with less precision, from salt precursors, but they catalyze a wider array of reactions than the iridium, typically being stable at higher temperatures and seemingly offering rich prospect for discovery of new catalysts.smaller to the atomic limit, the metals become cations anchored through metaloxygen or metal-carbon bonds. When all the metal atoms are accessible to reactants, they function with maximum efficiency and economy, and they have properties different from those in nanoparticles.Atomically dispersed supported metal catalysts have a long scientific and technological history. [1] Prominent industrial catalysts include oxophilic metals present as cations on oxide supports, illustrated by chromium complexes on silica for ethylene polymerization [2] and titanium cations in zeolite frameworks for propylene epoxidation. [3] However, the metals most widely applied in supported catalysts are noble-and expensive-typified by platinum and iridium. These are applied as supported nanoparticles. But now there is an explosion of research on atomically dispersed platinum and iridium. We assess it here. The intense interest reflects powerful, newly developed methods for fundamental research and tantalizing, yet unrealized, prospects for new applications of this class of material. Reports of supported platinum catalysts have long included high-resolution transmission electron microscopy (TEM) im...

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Controlling the Oxidation State of Pt Single Atoms for Maximizing Catalytic Activity

Cited by 149 publications

References 44 publications

Unique structure of active platinum-bismuth site for oxidation of carbon monoxide

Unique structure of active platinum-bismuth site for oxidation of carbon monoxide

Novel structure of active platinum-bismuth site for oxidation of carbon monoxide

Prototype Atomically Dispersed Supported Metal Catalysts: Iridium and Platinum

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