Experimental and modelling studies on the photocatalytic generation of hydrogen during water-splitting over a commercial TiO2 photocatalyst P25

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61989100%3A27710%2F21%3A10247944" target="_blank" >RIV/61989100:27710/21:10247944 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/60461373:22340/21:43923010

Výsledek na webu

<a href="https://www.sciencedirect.com/science/article/pii/S0196890421007585" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0196890421007585</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.enconman.2021.114582" target="_blank" >10.1016/j.enconman.2021.114582</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Experimental and modelling studies on the photocatalytic generation of hydrogen during water-splitting over a commercial TiO2 photocatalyst P25

Popis výsledku v původním jazyce

Hydrogen, generally perceived as an environmentally friendly fuel, possesses the potential to lower society&apos;s dependency on fossil energy sources whose utilization leads inherently to global warming problems. Its photocatalytic generation from aqueous solutions is a promising green technology competitive to traditionally employed methods such as steam reforming or water electrolysis. However, the limiting yet achievable efficiencies of this process remain unclear. To address the question of process efficiencies, we formulate a phenomenological model predicting the behavior of an experimental photocatalytic reactor. The model considers the polynomial light intensity distribution, the concentration of photocatalysts, and the finite rate of the mass transfer between liquid and gas phases. We validate the model against experimental data obtained from a study with a commercially available TiO2 P25 photocatalyst used as a gold standard in photocatalysis. The theoretical analysis shows that the mass transfer of hydrogen from the liquid to gas phase significantly affects the photoreactor dynamics. Initial accumulation of hydrogen in the liquid phase and its delayed transport to the gas phase result in a nonlinear time-dependence of the hydrogen concentration in the gas phase. The theoretical average reaction rate reaches a maximum for a photocatalyst concentration of 0.23 g/L, which is in good agreement with an experimentally obtained value of 0.25 g/L. The photonic efficiency, defined as a ratio of the average reaction rate to the average light intensity, also reaches a maximum at the same catalyst concentration and interestingly remains constant for any higher TiO2 loads. Finding the optimal photocatalyst concentration and identifying the critical role of mass transfer shall aid further research in developing and optimizing photocatalytic reactors for hydrogen production in the future.

Název v anglickém jazyce

Experimental and modelling studies on the photocatalytic generation of hydrogen during water-splitting over a commercial TiO2 photocatalyst P25

Popis výsledku anglicky

Hydrogen, generally perceived as an environmentally friendly fuel, possesses the potential to lower society&apos;s dependency on fossil energy sources whose utilization leads inherently to global warming problems. Its photocatalytic generation from aqueous solutions is a promising green technology competitive to traditionally employed methods such as steam reforming or water electrolysis. However, the limiting yet achievable efficiencies of this process remain unclear. To address the question of process efficiencies, we formulate a phenomenological model predicting the behavior of an experimental photocatalytic reactor. The model considers the polynomial light intensity distribution, the concentration of photocatalysts, and the finite rate of the mass transfer between liquid and gas phases. We validate the model against experimental data obtained from a study with a commercially available TiO2 P25 photocatalyst used as a gold standard in photocatalysis. The theoretical analysis shows that the mass transfer of hydrogen from the liquid to gas phase significantly affects the photoreactor dynamics. Initial accumulation of hydrogen in the liquid phase and its delayed transport to the gas phase result in a nonlinear time-dependence of the hydrogen concentration in the gas phase. The theoretical average reaction rate reaches a maximum for a photocatalyst concentration of 0.23 g/L, which is in good agreement with an experimentally obtained value of 0.25 g/L. The photonic efficiency, defined as a ratio of the average reaction rate to the average light intensity, also reaches a maximum at the same catalyst concentration and interestingly remains constant for any higher TiO2 loads. Finding the optimal photocatalyst concentration and identifying the critical role of mass transfer shall aid further research in developing and optimizing photocatalytic reactors for hydrogen production in the future.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

20402 - Chemical process engineering

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2021

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Energy Conversion and Management

ISSN

0196-8904

e-ISSN

—

Svazek periodika

245

Číslo periodika v rámci svazku

October

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

9

Strana od-do

—

Kód UT WoS článku

000693426900007

EID výsledku v databázi Scopus

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