Kinetic Modeling and Quantum Yields: Hydrogen Production via Pd-TiO2 Photocatalytic Water Splitting under Near-UV and Visible Light

Catalysts

Bianca Rusinque¹  Salvador Escobedo¹  Hugo de Lasa¹ 

[1] Chemical Reactor Engineering Centre (CREC), Faculty of Engineering, Western University, London, ON N6A 5B9, Canada;

关键词: palladium;    TiO₂;    hydrogen production;    visible light;    near-UV light;    photocatalysis;   

DOI  :  10.3390/catal12020113

来源: DOAJ

【 摘 要 】

A palladium (Pd) doped mesoporous titanium dioxide (TiO₂) photocatalyst was used to produce hydrogen (H₂) via water splitting under both near-UV and visible light. Experiments were carried out in the Photo-CREC Water-II Reactor (PCW-II) using a 0.25 wt% Pd-TiO₂ photocatalyst, initial pH = 4 and 2.0 v/v% ethanol, as an organic scavenger. After 6 h of near-UV irradiation, this photocatalyst yielded 113 cm³ STP of hydrogen (H₂). Furthermore, after 1 h of near-UV photoreduction followed by 5 h of visible light, the 0.25 wt% Pd-TiO₂ photocatalyst yielded 5.25 cm³ STP of H₂. The same photocatalyst, photoreduced for 24 h under near-UV and subsequently exposed to 5 h of visible light, yielded 29 cm³ STP of H₂. It was observed that the promoted redox reactions led to the production of hydrogen and by-products such as methane, ethane, ethylene, acetaldehyde, carbon monoxide, carbon dioxide and hydrogen peroxide. These redox reactions could be modeled using an “in series-parallel” reaction network and Langmuir Hinshelwood based kinetics. The proposed rate equations were validated using statistical analysis for the experimental data and calculated kinetic parameters. Furthermore, Quantum yields (${QY}_{H^{•}}\%$) based on the H^• produced were also established at promising levels: (a) 34.8% under near-UV light and 1.00 g L⁻¹ photocatalyst concentration; (b) 8.8% under visible light and 0.15 g L⁻¹. photocatalyst concentration following 24 h of near-UV.

【 授权许可】

Unknown