Advanced Photocatalysts: Pinning Single Atom Co‐Catalysts on Titania Nanotubes

Zhou, Xin; Hwang, Imgon; Tomanec, Ondřej; Fehn, Dominik; Mazare, Anca; Zbořil, Radek; Meyer, Karsten; Schmuki, Patrik

doi:10.1002/adfm.202102843

Cited by 58 publications

(67 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Note that the above definition [35,37] deviates from methods used in photocatalysis. [46] The Pt SA density was directly determined from the HAADF-TEM images, while also considering the reactive area to be represented by the illumination area (%1 cm 2 ).…”

Section: Supporting Informationmentioning

confidence: 99%

“…[29,35,36] Desired defects may either be intrinsically present in some substrates as a result of the synthesis procedure or can be introduced by defect engineering. [33,37,38] More recently, we reported that SAs can be attached to TiO 2 surfaces by trapping at suitable substrate defects. [29] Intrinsic defects of Ti 3þ -O v on TiO 2 nanotubes favor the stabilization of the isolated Pt atoms.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A Few Pt Single Atoms Are Responsible for the Overall Co‐Catalytic Activity in Pt/TiO₂ Photocatalytic H₂ Generation

et al. 2022

Self Cite

View full text Add to dashboard Cite

The use of single atoms (SAs) has become a highly investigated topic in heterogeneous catalysis, electrocatalysis, and most recently also in photocatalysis. In the field of photocatalysis, Pt SAs on TiO2 have been reported to be a highly efficient co‐catalyst in solar H2 production. Herein, the deposition of Pt SAs and nanoparticles on titania nanosheets is investigated. In particular, the Pt species responsible for the high co‐catalytic activity using a cyanide leaching process is elucidated. It is shown that neither Pt0 species nor the majority of Pt SAs do significantly contribute to the co‐catalytic activity of platinum on TiO2. In fact, >90% of the Pt of a standard deposition are non‐active and can be removed by cyanide leaching without activity loss—as a consequence, the remaining Pt SAs amount to a remarkable turnover frequency of 4.87 × 105 h−1 for H2 evolution.

show abstract

Section: Supporting Informationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A Few Pt Single Atoms Are Responsible for the Overall Co‐Catalytic Activity in Pt/TiO₂ Photocatalytic H₂ Generation

et al. 2022

Self Cite

View full text Add to dashboard Cite

show abstract

“…For example, Zhou et al showed that anodic growth of TiO 2 nanotubes poses a considerable strain on tube walls ensuing the formation of the high density of Ti 3+ -O v surface defects. 404 Taking advantage of defect-rich surface they pinned Ir SA sites by a simple impregnation approach. The resulting 0.58% IrSA TiO 2 catalyst displayed a turnover frequency of 4 × 10 6 h −1 .…”

Section: Photoactive Sacs For Ch 4 Ormentioning

confidence: 99%

Single Atom Catalysts for Selective Methane Oxidation to Oxygenates

Kumar

Al‐Attas

et al. 2022

ACS Nano

View full text Add to dashboard Cite

Direct conversion of methane (CH 4 ) to C 1−2 liquid oxygenates is a captivating approach to lock carbons in transportable value-added chemicals, while reducing global warming. Existing approaches utilizing the transformation of CH 4 to liquid fuel via tandemized steam methane reforming and the Fischer−Tropsch synthesis are energy and capital intensive. Chemocatalytic partial oxidation of methane remains challenging due to the negligible electron affinity, poor C−H bond polarizability, and high activation energy barrier. Transition-metal and stoichiometric catalysts utilizing harsh oxidants and reaction conditions perform poorly with randomized product distribution. Paradoxically, the catalysts which are active enough to break C−H also promote overoxidation, resulting in CO 2 generation and reduced carbon balance. Developing catalysts which can break C−H bonds of methane to selectively make useful chemicals at mild conditions is vital to commercialization. Single atom catalysts (SACs) with specifically coordinated metal centers on active support have displayed intrigued reactivity and selectivity for methane oxidation. SACs can significantly reduce the activation energy due to induced electrostatic polarization of the C−H bond to facilitate the accelerated reaction rate at the low reaction temperature. The distinct metal−support interaction can stabilize the intermediate and prevent the overoxidation of the reaction products. The present review accounts for recent progress in the field of SACs for the selective oxidation of CH 4 to C 1−2 oxygenates. The chemical nature of catalytic sites, effects of metal−support interaction, and stabilization of intermediate species on catalysts to minimize overoxidation are thoroughly discussed with a forward-looking perspective to improve the catalytic performance.

show abstract

“…[ 32,33 ] In contrast to these approaches, we recently reported that SA trapping can be achieved on defect‐engineered TiO 2 layers [ 34–36 ] or defects of TiO 2 nanotubes grown by anodization on Ti metal. [ 37–39 ]…”

Section: Introductionmentioning

confidence: 99%

Pt Single Atoms on TiO₂ Polymorphs—Minimum Loading with a Maximized Photocatalytic Efficiency

Qin

Denisov

Sarma

et al. 2022

Adv Materials Inter

Self Cite

View full text Add to dashboard Cite

For more than 20 years, Pt/TiO2 represents the benchmark photocatalyst/co‐catalyst platform for photocatalytic hydrogen (H2) generation. Here, single atom (SA) Pt is decorated on different polymorphs of TiO2 (anatase, rutile, and the mixed phase of P25) using a simple immersion anchoring approach. On P25 and anatase, Pt SAs act as highly effective co‐catalyst for pure water splitting with a photocatalytic H2 evolution activity (4600 µmol h−1 g−1)—on both polymorphs, SA deposition yields a significantly more active photocatalyst than those decorated with classic Pt nanoparticles or conventional SA deposition approaches. On rutile, Pt SAs provide hardly any co‐catalytic effect. Most remarkable, for P25, the loading of Pt SAs from precursor solution with a very low concentration (<1 ppm Pt) leads already to a maximized co‐catalytic effect. This optimized efficiency is obtained at 5.3 × 105 atoms µm−2 (at macroscopic loading of 0.06 at%)—for a higher concentration of Pt (a higher density of SAs), the co‐catalytic efficiency is significantly reduced due to H2/O2 recombination. The interactions of the SA Pt with the different polymorphs that lead to this high co‐catalytic activity of SA Pt at such low concentrations are further discussed.

show abstract

Advanced Photocatalysts: Pinning Single Atom Co‐Catalysts on Titania Nanotubes

Cited by 58 publications

References 48 publications

A Few Pt Single Atoms Are Responsible for the Overall Co‐Catalytic Activity in Pt/TiO₂ Photocatalytic H₂ Generation

A Few Pt Single Atoms Are Responsible for the Overall Co‐Catalytic Activity in Pt/TiO₂ Photocatalytic H₂ Generation

Single Atom Catalysts for Selective Methane Oxidation to Oxygenates

Pt Single Atoms on TiO₂ Polymorphs—Minimum Loading with a Maximized Photocatalytic Efficiency

Contact Info

Product

Resources

About

Advanced Photocatalysts: Pinning Single Atom Co‐Catalysts on Titania Nanotubes

Cited by 58 publications

References 48 publications

A Few Pt Single Atoms Are Responsible for the Overall Co‐Catalytic Activity in Pt/TiO2 Photocatalytic H2 Generation

A Few Pt Single Atoms Are Responsible for the Overall Co‐Catalytic Activity in Pt/TiO2 Photocatalytic H2 Generation

Single Atom Catalysts for Selective Methane Oxidation to Oxygenates

Pt Single Atoms on TiO2 Polymorphs—Minimum Loading with a Maximized Photocatalytic Efficiency

Contact Info

Product

Resources

About

A Few Pt Single Atoms Are Responsible for the Overall Co‐Catalytic Activity in Pt/TiO₂ Photocatalytic H₂ Generation

A Few Pt Single Atoms Are Responsible for the Overall Co‐Catalytic Activity in Pt/TiO₂ Photocatalytic H₂ Generation

Pt Single Atoms on TiO₂ Polymorphs—Minimum Loading with a Maximized Photocatalytic Efficiency