Photocatalytic reforming of glycerol to H2 in a thin film Pt-TiO2 recirculating photoreactor

Abstract

BACKGROUND: With an increase in global bioenergy production, the ‘biorefinery concept’ has now become a significant focus of research. The desire to achieve efficient conversion of biomass material into both energy and value-added products requires a combination of technologies and processes. As such, the photocatalytic reforming of feedstocks such as glycerol to hydrogen (H2) has a lot of potential. RESULTS: Reported here is the first example of a thin film-based photocatalytic system capable of achieving H2 evolution using a glycerol feedstock. Using a titania (TiO2) sol–gel, glass columns were coated with a thin TiO2 layer before using photodeposition to add platinum (Pt) as a co-catalyst. The coated columns were assembled into a simple yet effective recirculating system which used low power UV irradiation. Under optimum conditions (two coated columns and a 40 mL min−1 flow rate), a steady state of 0.9 μmol min−1 H2 with a photonic efficiency [ηphoton (%)] of 10.22 % was achieved. Furthermore, only one column showed flaking and loss of coating whereas the remaining columns were stable for the duration of the study, which equated to > 100 h of experimental testing including replicates and determining optimal parameters. CONCLUSION: H2 evolution via photocatalytic glycerol reforming in a Pt-TiO2 thin film catalyst recirculating system has been demonstrated under UV irradiation and ambient conditions. The system developed highlights that it is both catalyst development and reactor engineering that are required to continue to advance the field of photocatalysis. © 2020 The Authors. Journal of Chemical Technology & Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.