Effect of polar and movable (OH or NH₂ groups) on the photocatalytic H₂ production of alkyl-alkanolamine

A comparative study

authored by

A.F. Alkaim, R. Dillert, D.W. Bahnemann

Abstract

The photocatalytic production of molecular hydrogen (H

₂) from aqueous solutions of alkyl-alkanolamines (triethanolamine (tri-EOA), diethanolamine (di-EOA), ethanolamine (EOA), ethylamine (EA) and ethanol over Pt-loaded commercial (Sachtleben Hombikat UV100) nanoparticle titanium dioxide photocatalysts was studied. These photocatalysts were characterized using X-ray diffraction, Brunauer-Emmett-Teller, field-emission scanning electron microscopy, atomic force microscopy and UV-vis diffuse reflectance spectroscopy techniques. Effect of pH and temperature on photocatalytic hydrogen production of alkyl-alkanolamines was investigated. It was found for all molecules under study that the amount of hydrogen produced at a constant illumination time is a function of pH and temperature. At all temperatures investigated the rate of hydrogen production at pH 9 followed the order tri-EOAethanolamine >> di-EOA ≈ EOA > ethanol > EA. From the values of the photocatalytic rate constants at various temperatures, the apparent activation energies were determined for the hydrogen production. The observed dependence ofthe reaction rate on solution temperature cannot be related to light-driven reaction steps, because the band-gap energy of the semiconductor is too high for thermal excitation to become significant in the temperature range investigated.

Organisation(s)

Institute of Technical Chemistry

Type

Article

Journal

Environmental Technology (United Kingdom)

Volume

36

Pages

2190-2197

No. of pages

8

ISSN

0959-3330

Publication date

02.09.2015

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Environmental Chemistry, Water Science and Technology, Waste Management and Disposal

Sustainable Development Goals

SDG 7 - Affordable and Clean Energy

Electronic version(s)

https://doi.org/10.1080/09593330.2015.1024757 (Access: Closed)