Operational Conditions Affecting Formaldehyde and Formic Acid Formation as By‐Products of Hydrogen Production via Photo‐Reforming of Methanol Using Nanoparticles of TiO2

• Published in: Energy technology (Weinheim, Germany) Germany), 2018-10, Vol.6 (10), p.1871-1884
• Main Authors: Varas‐Concha, Felipe, Guzmán, Diego, Isaacs, Mauricio, Sáez‐Navarrete, César
• Format: Article
• Language: English
• Subjects: Catalysis; Catalysts; Cobalt; Formaldehyde; Formic acid; Fractional factorial experiment; Gold; Gold nanoparticles; Hydrogen production; Luminous intensity; Methanol; Nanoparticles; Photo-reforming of methanol; Photocatalysis; Reforming; Shielding; Titanium dioxide; Titanium dioxide nanoparticles
• ISSN: 2194-4288; 2194-4296
• DOI: 10.1002/ente.201700853

It is important to understand how the operational conditions affect the photocatalytic hydrogen production and how to increase the production of valuable by‐products, such as formaldehyde and formic acid from the photo‐reforming of methanol. It is difficult to optimize operational conditions in photoreactors because several factors affect the process. To prioritize them, we focused on the quantification of the effect of four factors on CH2O and CH2O2 production: (A) presence of gold as co‐catalyst, (B) intensity of UV‐light, (C) methanol concentration, and (D) nanoparticle concentration. A main and interaction effects analysis is presented with fixed effect models for four responses: total production and catalyst productivity for both by‐products. Factor A showed the highest effect, followed by factors B and C, and the interactions AB and AC showed signs of influencing the catalyst selectivity with possible mechanistic variations. Factor D showed negative effect on catalyst productivities possibly related to shielding effect between particles. What operational condition really matters? A statistical approach is used to identify the heaviest factors affecting the photocatalytic production of formaldehyde and formic acid, by‐products from hydrogen generation via photoreforming of methanol using TiO2 nanoparticles. Among 4 factors and their interactions, presence of gold as a co‐catalyst, light radiation and nanoparticles of methanol result to be the critical and most important factors.