Comparison of hydrothermal and photocatalytic conversion of glucose with commercial TiO2: Superficial properties-activities relationships

Abstract

Recently, the photocatalytic conversion of glucose appeared as an environmentally friendly route to produce valuable molecules. However, the potential of this new route in comparison with the usual hydrothermal catalytic process remained questionable. In this paper, we compared the two routes using three commercial TiO 2 as catalysts in the same reactor. The TiO 2 superficial acidity and basicity were determined by calorimetry and FTIR of CO 2 , NH 3 and pyridine adsorption. Relationships between the acid-base properties, the TiO 2 glucose adsorption capacities measured in water and their photocatalytic or hydrothermal performances were proposed: while the photocatalytic performances could be linked to the catalysts' Lewis acid sites density and their glucose adsorption capacities, the hydrothermal performances were dependent of the catalysts' basic/acid sites balance. We highlighted that the conversion of glucose over TiO 2 was as efficient with the photocatalytic process at ambient temperature as with the hydrothermal process at 120°C. This underlines the potential of the photocatalytic route at the lab scale as regards to the milder experimental conditions involved.

A TiO2‐Co(terpyridine)2 Photocatalyst for the Selective Oxidation of Cellulose to Formate Coupled to the Reduction of CO2 to Syngas

“…FT‐IR spectra of the solid showed that the vibrational bands corresponding to the terpyridine ligands of CotpyP (1571, 1587, 1602 cm −1 ) [29] were still present after photocatalysis, but with a seemingly lower intensity (Figure S17). The changes in the vibrational spectra when using glucose compared to TEOA may be explained by glucose interacting more strongly with the TiO 2 surface and more readily disturbing the interaction between CotpyP and TiO 2 [48] …”

Hydrothermal process assisted by photocatalysis: Towards a novel hybrid mechanism driven glucose valorization to levulinic acid, ethylene and hydrogen

“…While the PDAD was used to detect the carboxylic acids and furanic compounds at 210 nm (Fig. S1) [31]. Butyric acid was used as internal standard.…”

“…It consisted in the mineralization of the organic compounds at 720 °C catalyzed by Pt/Al 2 O 3 into CO 2 that was then quantified by IR detector. The carbon balance was then calculated by dividing the TOC measured at the end of reaction (final TOC) by the initial TOC [31].…”

“…The physico-chemical properties of the commercial TiO 2 , UV100 and Rut160, were investigated elsewhere [31]. They are recalled in Table 1.…”

A Landscape of Lignocellulosic Biopolymer Transformations into Valuable Molecules by Heterogeneous Catalysis in C’Durable Team at IRCELYON

“…We particularly use heterogeneous catalysis, which is a primordial tool to implement sustainable procedures [3][4][5][6]. Initial works in the team focused on upgrading first generation biomass like vegetable oils [7][8][9][10], starch [11][12][13][14], glycerol [15][16][17][18][19][20][21], simple saccharides [22][23][24][25][26][27][28][29][30][31], and their furan derivatives [32][33][34]. Studies involving second generation biomass, especially lignocellulose (wood and grassy plants), have started more recently and are now predominant.…”