Mechanisms of Simultaneous Hydrogen Production and Formaldehyde Oxidation in H2O and D2O over Platinized TiO2

Hamza Belhadj, Saher Hamid, Peter K. J. Robertson, Detlef W. Bahnemann

Research output: Contribution to journalArticlepeer-review

32 Citations (Scopus)
395 Downloads (Pure)

Abstract

The simultaneous photocatalytic degradation of formaldehyde and hydrogen evolution on platinized TiO2 have been investigated employing different mixtures of H2O-D2O under oxygen free conditions using Quadrupole Mass Spectrometery (QMS) and Attenuated Total Reflection Fourier Transformed Infrared spectroscopy (ATR-FTIR). The main reaction products obtained from the photocatalytic oxidation of 20% formaldehyde were hydrogen and carbon dioxide. The ratio of evolved H2 to CO2 was to 2 to 1. The HD gas yield was found to be dependent on the solvent and was maximised in a mixture of H2O:D2O (20%:80%). The study of the solvent isotope effect on the degradation of formaldehyde indicates that the mineralization rate of formaldehyde (CO2) decreases considerably when increasing the concentration of D2O. Based on the ATR-FTIR data, the formaldehyde in D2O is gradually converted to deuterated formic acid during UV irradiation which was confirmed by different band shifting. An additional FTIR band at 2050 cm-1 assigned to CO was detected and was found to increase during UV irradiation due to the adsorption of molecular CO on Pt/TiO2. The results of these investigations showed that the molecular hydrogen is mainly produced by the reduction of two protons originating from water and formaldehyde. A detailed mechanism for the simultaneous hydrogen production and formaldehyde oxidation in D2O is also presented.
Original languageEnglish
Pages (from-to)4753-4758
JournalACS Catalysis
Volume7
Early online date05 Jun 2017
DOIs
Publication statusPublished - 2017

Keywords

  • Pt/TiO2, Hydrogen Production, D2O, Formaldehyde, Photocatalytic reaction.

Fingerprint

Dive into the research topics of 'Mechanisms of Simultaneous Hydrogen Production and Formaldehyde Oxidation in H2O and D2O over Platinized TiO2'. Together they form a unique fingerprint.

Cite this