Study of PtOx/TiO2 Photocatalysts in the Photocatalytic Reforming of Glycerol: The Role of Co-Catalyst Formation

In this study, relationships between preparation conditions, structure, and activity of Pt-containing TiO2 photocatalysts in photoinduced reforming of glycerol for H2 production were explored. Commercial Aerolyst® TiO2 (P25) and homemade TiO2 prepared by precipitation-aging method were used as semiconductors. Pt co-catalysts were prepared by incipient wetness impregnation from aqueous solution of Pt(NH3)4(NO3)2 and activated by calcination, high temperature hydrogen, or nitrogen treatments. The chemico-physical and structural properties were evaluated by XRD, 1H MAS NMR, ESR, XPS, TG-MS and TEM. The highest H2 evolution rate was observed over P25 based samples and the H2 treatment resulted in more active samples than the other co-catalyst formation methods. In all calcined samples, reduction of Pt occurred during the photocatalytic reaction. Platinum was more easily reducible in all of the P25 supported samples compared to those obtained from the more water-retentive homemade TiO2. This result was related to the negative effect of the adsorbed water content of the homemade TiO2 on Pt reduction and on particle growth during co-catalyst formation.

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Ultrathin Ni(ii)-based coordination polymer nanosheets as a co-catalyst for promoting photocatalytic H2-production

Chemical Communications ◽

10.1039/c9cc02680k ◽

2019 ◽

Vol 55 (46) ◽

pp. 6499-6502 ◽

Cited By ~ 8

Author(s):

Zhi-Qiang Jiang ◽

Xing-Liang Chen ◽

Jin Lu ◽

Yu-Feng Li ◽

Tian Wen ◽

...

Keyword(s):

Hydrogen Production ◽

Coordination Polymer ◽

Visible Light ◽

H2 Production ◽

Co Catalyst ◽

Photocatalytic Hydrogen Production ◽

Co Catalysts ◽

Production Activity ◽

Visible Light Photocatalytic

The Ni(ii) coordination polymer nanosheets were successfully exfoliated, which can be used as co-catalysts (Ni-CPNS@CdS). The optimized Ni-CPNS@CdS catalyst showed a super high visible-light photocatalytic hydrogen production activity.

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Copper(i) cysteine complexes: efficient earth-abundant oxidation co-catalysts for visible light-driven photocatalytic H2 production

Chemical Communications ◽

10.1039/c5cc04739k ◽

2015 ◽

Vol 51 (63) ◽

pp. 12556-12559 ◽

Cited By ~ 28

Author(s):

Yong Peng ◽

Lu Shang ◽

Yitao Cao ◽

Geoffrey I. N. Waterhouse ◽

Chao Zhou ◽

...

Keyword(s):

Visible Light ◽

H2 Production ◽

Co Catalyst ◽

Co Catalysts ◽

Highly Efficient ◽

Earth Abundant ◽

Visible Light Driven

Inspired by nature, a Cu(i)–cysteine complex serving as an oxidation co-catalyst to consume photo-induced holes has been developed for highly efficient visible light-driven photocatalytic H2 production.

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Double-Nozzle Flame Spray Pyrolysis as a Potent Technology to Engineer Noble Metal-TiO2 Nanophotocatalysts for Efficient H2 Production

Energies ◽

10.3390/en14040817 ◽

2021 ◽

Vol 14 (4) ◽

pp. 817

Author(s):

Maria Solakidou ◽

Yiannis Georgiou ◽

Yiannis Deligiannakis

Keyword(s):

Spray Pyrolysis ◽

Noble Metal ◽

H2 Production ◽

Flame Spray Pyrolysis ◽

Flame Spray ◽

Scale Production ◽

Efficient Technology ◽

Tio2 Photocatalysts ◽

Surface Dispersion ◽

Tio2 Matrix

Noble metal-TiO2 nanohybrids, NM0-TiO2, (NM0 = Pt0, Pd0, Au0, Ag0) have been engineered by One-Nozzle Flame Spray Pyrolysis (ON-FSP) and Double-Nozzle Flame Spray Pyrolysis (DN-FSP), by controlling the method of noble metal deposition to the TiO2 matrix. A comparative screening of the two FSP methods was realized, using the NM0-TiO2 photocatalysts for H2 production from H2O/methanol. The results show that the DN-FSP process allows engineering of more efficient NM0-TiO2 nanophotocatalysts. This is attributed to the better surface-dispersion and narrower size-distribution of the noble metal onto the TiO2 matrix. In addition, DN-FSP process promoted the formation of intraband states in NM0-TiO2, lowering the band-gap of the nanophotocatalysts. Thus, the present study demonstrates that DN-FSP process is a highly efficient technology for fine engineering of photocatalysts, which adds up to the inherent scalability of Flame Spray Pyrolysis towards industrial-scale production of nanophotocatalysts.

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Role of Mixed Oxides in Hydrogen Production through the Dry Reforming of Methane over Nickel Catalysts Supported on Modified γ-Al2O3

Processes ◽

10.3390/pr9010157 ◽

2021 ◽

Vol 9 (1) ◽

pp. 157

Author(s):

Ahmed Sadeq Al-Fatesh ◽

Mayankkumar Lakshmanbhai Chaudhary ◽

Anis Hamza Fakeeha ◽

Ahmed Aidid Ibrahim ◽

Fahad Al-Mubaddel ◽

...

Keyword(s):

Mixed Oxides ◽

Nickel Catalysts ◽

H2 Production ◽

Dry Reforming ◽

Dry Reforming Of Methane ◽

Incipient Wetness Impregnation ◽

Thermally Stable ◽

Oxide Systems ◽

Catalyst Systems ◽

H2 Yield

H2 production through dry reforming of methane (DRM) is a hot topic amidst growing environmental and atom-economy concerns. Loading Ni-based reducible mixed oxide systems onto a thermally stable support is a reliable approach for obtaining catalysts of good dispersion and high stability. Herein, NiO was dispersed over MOx-modified-γ-Al2O3 (M = Ti, Mo, Si, or W; x = 2 or 3) through incipient wetness impregnation followed by calcination. The obtained catalyst systems were characterized by infrared, ultraviolet–visible, and X-ray photoelectron spectroscopies, and H2 temperature-programmed reduction. The mentioned synthetic procedure afforded the proper nucleation of different NiO-containing mixed oxides and/or interacting-NiO species. With different modifiers, the interaction of NiO with the γ-Al2O3 support was found to change, the Ni2+ environment was reformed exclusively, and the tendency of NiO species to undergo reduction was modified greatly. Catalyst systems 5Ni3MAl (M = Si, W) comprised a variety of species, whereby NiO interacted with the modifier and the support (e.g., NiSiO3, NiAl2O4, and NiWO3). These two catalyst systems displayed equal efficiency, >70% H2 yield at 800 °C, and were thermally stable for up to 420 min on stream. 5Ni3SiAl catalyst regained nearly all its activity during regeneration for up to two cycles.

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Positive effects of a halloysite-supported Cu/Co catalyst fabricated by a urea-driven deposition precipitation method on the CO-SCR reaction and SO2 poisoning

Catalysis Science & Technology ◽

10.1039/d0cy02261f ◽

2021 ◽

Author(s):

Wei-Jing Li ◽

Shu Tsai ◽

Ming-Yen Wey

Keyword(s):

Co Oxidation ◽

Catalytic Reduction ◽

Precipitation Method ◽

Molar Ratio ◽

Halloysite Nanotube ◽

Co Catalyst ◽

Reduction Of No ◽

Co Catalysts ◽

Positive Effects ◽

So2 Poisoning

Cu/Co catalysts were prepared on halloysite nanotube supports by a urea-driven deposition-precipitation method for CO oxidation and the selective catalytic reduction of NO (CO-SCR). First, the Cu/NH3 molar ratio was...

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Controlling the performance of a silver co-catalyst by a palladium core in TiO2-photocatalyzed alkyne semihydrogenation and H2 production

Applied Catalysis A General ◽

10.1016/j.apcata.2021.118331 ◽

2021 ◽

pp. 118331

Author(s):

Shota Imai ◽

Yasumi Kojima ◽

Eri Fudo ◽

Atsuhiro Tanaka ◽

Hiroshi Kominami

Keyword(s):

H2 Production ◽

Co Catalyst

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C-,N- and S-Doped TiO2 Photocatalysts: A Review

Catalysts ◽

10.3390/catal11010144 ◽

2021 ◽

Vol 11 (1) ◽

pp. 144

Author(s):

Aleksandra Piątkowska ◽

Magdalena Janus ◽

Kacper Szymański ◽

Sylwia Mozia

Keyword(s):

Carbon Dioxide Reduction ◽

Air Purification ◽

Lithium Storage ◽

Tio2 Photocatalysts ◽

Doped Tio2 ◽

Preparation Conditions ◽

Production Of Hydrogen ◽

Methods Of Synthesis ◽

Metal Doped ◽

Inactivation Of Bacteria

This article presents an overview of the reports on the doping of TiO2 with carbon, nitrogen, and sulfur, including single, co-, and tri-doping. A comparison of the properties of the photocatalysts synthesized from various precursors of TiO2 and C, N, or S dopants is summarized. Selected methods of synthesis of the non-metal doped TiO2 are also described. Furthermore, the influence of the preparation conditions on the doping mode (interstitial or substitutional) with reference to various types of the modified TiO2 is summarized. The mechanisms of photocatalysis for the different modes of the non-metal doping are also discussed. Moreover, selected applications of the non-metal doped TiO2 photocatalysts are shown, including the removal of organic compounds from water/wastewater, air purification, production of hydrogen, lithium storage, inactivation of bacteria, or carbon dioxide reduction.

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Use of (R)-Mandelic Acid as Chiral Co-Catalyst in the Michael Addition Reaction Organocatalyzed by (1S,4S)-2-Tosyl-2,5-diazabicyclo[2.2.1]heptane under Solvent-Free Conditions

Asymmetric Catalysis ◽

10.1515/asorg-2015-0004 ◽

2015 ◽

Vol 2 (1) ◽

Cited By ~ 4

Author(s):

C. Gabriela Ávila-Ortiz ◽

Manuel López-Ortiz ◽

Alberto Vega-Peñaloza ◽

Ignacio Regla ◽

Eusebio Juaristi

Keyword(s):

Michael Addition ◽

Mandelic Acid ◽

Addition Reaction ◽

Solvent Free ◽

Reaction Intermediates ◽

Michael Addition Reaction ◽

Co Catalyst ◽

Co Catalysts ◽

Solvent Free Conditions ◽

The Michael Addition

AbstractThis article describes a study on the Michael addition reaction of cyclohexanone to nitroolefins catalyzed by the chiral secondary amine (1S,4S)-2-tosyl- 2,5-diazabicyclo[2.2.1]heptane. Reactions were carried out under solvent-free conditions to make them more environmentally friendly. Initially, the observed diastereoand enantioselectivities were moderate to good, but were significantly improved by lowering the reaction temperature. Furthermore, a variety of chiral acids were also tested as co-catalysts in both of their enantiomeric forms, which revealed that (R)-mandelic acid affords excellent results in terms of yield and stereoselectivity. Monitoring the reaction by MS-TOF allowed for the detection of key reaction intermediates, and a reasonable reaction mechanism in which both catalysts are involved is proposed.

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