Efficiency of thermo–photocatalytic production of hydrogen from biomolecules: a multifaceted perspective

Abstract

Measuring and interpreting efficiency of a thermo-photo catalytic reaction appear as central pieces in the quest to define synergy for chemical reactions taking place under dual thermo-photo excitation. The analysis...

Green Thermo-Photo Catalytic Production of Syngas Using Pd/Nb–TiO2 Catalysts

“…The maximum quantum efficiency reaches ca. 25–35% for most of the samples of the series, a range not able to be obtained for any sample under the light-alone excitation. ,,, We would like to stress that for the calculation of the quantum efficiency, all temperature and light-related effects are considered quantitatively, as detailed in the Supporting Information section. , …”

“…Full details of the calculation of the parameters described can be found in refs and and are fully described in the Supporting Information section.…”

“…The relatively high temperature required for operation of benchmark catalysis based in noble (Pt and Rh) and non-noble (Cu and Ni) supported on reducible oxides as well as the concomitant deactivation effects on the currently available catalysts are issues which do not allow practical implementation of the process at the present stage. ,, Alternatively, photo-based activation and transformation of the alcohol can be carried out at room temperature and pressure. However, several physico-chemical phenomena such as the significant charge recombination after illumination or a sluggish kinetics with multiple and successive steps consuming a significant number of charge carrier species limit efficiency and correspond to a major issue for technological application of photocatalysis. , Irrespective of the energy source of the methanol-based catalytic process, a combination of light and thermal energy sources can mitigate or eliminate some of the main controlling factors limiting the practical implementation of single-energy source thermal- and photo-alone processes. − As a consequence, in recent years, the thermo-photo catalytic production of hydrogen and syngas has been actively investigated. − Among tested catalytic powders, TiO 2 -based materials have been broadly used due to the well-known adequate properties of the oxide, both in the thermal and photonic alone processes. , Both noble metal ,− and non-noble metal ,− co-catalysts are customarily used for TiO 2 -based catalysts in order to boost activity. Among them, the study of Pd is scarcely investigated for the production of hydrogen, although has been already tested for volatile organic elimination using thermo-photo catalysis …”

“…27,34,40,41 We would like to stress that for the calculation of the quantum efficiency, all temperature and light-related effects are considered quantitatively, as detailed in the Supporting Information section. 12,39 Valuable insights concerning the performance of the samples for hydrogen generation can be additionally obtained from the excess parameters (eqs 2 and 3). For the catalysts of the series, the plots at the bottom row of Figure 1 (panels C/D) present the evolution of the excess reaction rate and quantum efficiency parameters as a function of the temperature.…”

Photothermal Boosting of Photocatalytic Hydrogen Evolution Induced by Defects and Cocatalysts on TiO2

“…The heat associated with solar radiation should also contribute to an increase in the temperature of the reaction system and/or the catalysts themselves, thereby increasing the photocatalysis rate. Indeed, the effects of an increase in temperature of the overall reaction system (e.g., light absorption by the reaction solution) on photocatalytic activity under irradiation with solar or concentrated light have been reported. , However, material-design approaches to actively utilize visible-infrared (IR) light with wavelengths longer than the absorption edge of the semiconductor photocatalysts as heat have been limited. The incorporation of carbon or plasmonic nanoparticles into the photocatalysts is an example of exploiting the photothermal effects of materials, rather than water, to enhance their photocatalytic activity .…”