Hydrogen Photoproduction from Ethanol–Water Mixtures Over Au–Cu Alloy Nanoparticles Supported on TiO2

Bonmatí, Eduard; Casanovas, Albert; Angurell, Inmaculada; Llorca, Jordi

doi:10.1007/s11244-014-0347-8

Cited by 22 publications

(27 citation statements)

References 41 publications

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“…given by Hutchings and co-workers, who discovered the superior performance of Pdshell-Aucore nanoparticles immobilised on TiO2 exhibiting high photoreforming quantum efficiencies as compared to random alloy or Aushell-Pdcore counterparts, using a range of biomass-derived alcohols or saccharides (reaching Φ ≈ 78% for glycerol, see micrographs in Figure 25) [287]. Llorca and coworkers systematically studied gold-copper alloys for ethanol photoreforming, and found an optimum composition at a 3:1 Au/Cu atomic ratio [288]. Another thorough investigation on Ptcontaining alloy nanoparticles using either TiO2 or CdS as the semiconducting supports was performed by Hu and Yu.…”

Section: Co-catalyst Engineering For H2 Productionmentioning

confidence: 99%

Photocatalytic production of hydrogen from biomass-derived feedstocks

Puga

2016

Coordination Chemistry Reviews

380

270

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The application of photocatalysis for the utilisation of sunlight energy is intensely investigated in present times, particularly in prospect of generating solar fuels by hydrogen production or CO2 reduction processes as tools for societies aiming to relief their thirst for fossil resources. From the perspective of sustainability, the rational use of biomass-derived feedstocks for photocatalytic H2 production is a feasible, proven and highly efficient process. In this review, in addition to delving into physico-chemical fundamentals of photocatalytic processes on semiconductors, the research activity on this topic related to design of revolutionary semiconductor-based materials, generally including metallic nanoparticles or complexes as hydrogen-evolving co-catalysts, is outlined and critically evaluated. Moreover, the use of sunlight and renewable feedstocks for the generation of hydrogen, as a compelling opportunity for the energy sector, is emphasised. Special focus is also set on the valorisation of biorefinery products, agricultural residues and industrial or municipal waste.

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Section: Co-catalyst Engineering For H2 Productionmentioning

confidence: 99%

Photocatalytic production of hydrogen from biomass-derived feedstocks

Puga

2016

Coordination Chemistry Reviews

380

270

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“…This value was selected following previous studies, where an optimum Au loading of 1-2 wt.% was found [6,12,13]. The pre-formed Au nanoparticles consisted of metallic Au cores covered by a protective shell of dodecanethiol and were prepared as reported previously [7]. Briefly, AuCl 4 was first transferred from aqueous HAuCl 4 solution (40 mM) to toluene solution using tetraoctylammonium bromide as a phase transfer reagent.…”

Section: Fabrication Of the Photocatalytic Silicone Microreactorsmentioning

confidence: 99%

“…The normalized hydrogen photogeneration rate obtained in the silicone photomicroreactor was . Using exactly the same photocatalyst and gaseous mixture (10% EtOH, molar basis), the normalized hydrogen photogeneration rate obtained in an optical fiber honeycomb photoreactor was [7].…”

Section: Characterization Of the Photocatalyst And The Microreactormentioning

confidence: 99%

“…Several solutions have been proposed to overcome the photon transfer limitations without sacrificing mass transport, such as the use of optical fibers inside photocatalytic honeycombs [5][6][7] and conventional optofluidic devices made out of quartz or Pyrex with microchannels made by either micro-milling, etching processes or laser ablation [8,9]. In these devices, in addition to increasing reaction rates by improving both mass and optical transfer efficiencies, the photocatalyst is immobilized on the reactor walls and no recovery is necessary.…”

Section: Introductionmentioning

confidence: 99%

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Silicone microreactors for the photocatalytic generation of hydrogen

et al. 2016

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A silicone microreactor with 500 mu m-width microchannels coated with a Au/TiO2 photocatalyst was manufactured and tested for the photocatalytic generation of hydrogen from gaseous water-ethanol mixtures under dynamic conditions. The manufacture of the microreactor included the fabrication of a polylactic acid (PLA) mold with a 3D printer and casting with polydimethylsiloxane (PDMS) prepolymer. After curing, the silicone microreactor was peeled off and the microchannels were coated with a Au/TiO2 photocatalyst prepared by impregnation of preformed Au nanoparticles over TiO2, and sealed with a thin silicone cover. The microreactor was tested at room temperature and atmospheric pressure under different operational conditions (photon irradiance, residence time, photocatalyst loading, and water ethanol ratio). Hydrogen production rates of 5.4 NmL W-1 h(-1) were measured at a residence time of 0.35 s using a H2O:C2H5OH molar ratio of 9:1, a photocatalyst load of 1.2 mg cm(-2) and a UV irradiance (365 nm) of 1.5 mW cm(-2) achieving an apparent quantum efficiency of 9.2%. The photogeneration of hydrogen with commercial bioethanol was also tested. A long-term photocatalytic test of two days revealed a stable hydrogen photoproduction rate. The use of silicone microreactors represents an attractive and customizable solution for conducting photochemical reactions for producing hydrogen at low cost. (C) 2016 Elsevier B.V. All rights reserved.Postprint (published version

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“…In order to maximize the reactant-catalyst contact and the illumination efficiency, two microreactor systems have been developed by our group, where gas-solid reactions were conducted for the photogeneration of hydrogen using waterethanol gaseous mixtures and an Au/TiO 2 photocatalyst. One of them consisted on a honeycomb photoreactor with optical fibers inside the honeycomb cells [10][11][12], where an excellent photon delivery was achieved. More recently, we have manufactured a silicone microreactor with microchannels using a simple, versatile and cheap technology based on 3D printing and polydimethylsiloxane (PDMS) polymerization.…”

Section: Introductionmentioning

confidence: 99%

Kinetic analysis and CFD simulations of the photocatalytic production of hydrogen in silicone microreactors from water-ethanol mixtures

Castedo

Uriz

Soler

et al. 2017

Applied Catalysis B: Environmental

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Silicone microreactors containing microchannels of 500 µm width in a single or triple stack configuration have been manufactured, coated with an Au/TiO2 photocatalyst and tested for the photocatalytic production of hydrogen from water-ethanol gaseous mixtures under UV irradiation. Computational fluid dynamics (CFD) simulations have revealed that the design of the distributing headers allowed for a homogeneous distribution of the gaseous stream within the channels of the microreactors. A rate equation for the photocatalytic reaction has been developed from the experimental results obtained with the single stack operated under different ethanol partial pressures, light irradiation intensities and contact times. The hydrogen photoproduction rate has been expressed in terms of a Langmuir-Hinshelwood-type equation that accurately describes the process considering that hydrogen is produced through the dehydrogenation of ethanol to acetaldehyde. This equation incorporates an apparent rate constant (kapp) that has been found to be proportional to the intrinsic kinetic rate constant (k), and that depends on the light intensity (I) as follows: kapp = k·I0.65. A three-dimensional isothermal CFD model has been developed in which the previously obtained kinetic equation has been implemented. The model adequately describes the production of hydrogen of both the single and triple stacks. Moreover, the specific hydrogen productions (i.e. per gram of catalyst) are very close for both stacks thus suggesting that the scaling-up of the process could be accomplished by simply numbering-up. However, small deviations between the experimental and predicted hydrogen production suggest that a fraction of the radiation is absorbed by the microreactor components which should be taken into account for scaling-up purposes.Postprint (author's final draft

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Hydrogen Photoproduction from Ethanol–Water Mixtures Over Au–Cu Alloy Nanoparticles Supported on TiO2

Cited by 22 publications

References 41 publications

Photocatalytic production of hydrogen from biomass-derived feedstocks

Photocatalytic production of hydrogen from biomass-derived feedstocks

Silicone microreactors for the photocatalytic generation of hydrogen

Kinetic analysis and CFD simulations of the photocatalytic production of hydrogen in silicone microreactors from water-ethanol mixtures

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