Investigation on the effect of temperature on photothermal glycerol reforming hydrogen production over Ag/TiO2 nanoflake catalyst

Abstract

Photothermal reforming of biomass-derived hydrocarbons is an efficient approach to generate renewable hydrogen driven by solar. However, the current understanding of the general thermal effect on hydrogen production is limited since the photothermal and thermal radiation from solar is difficult to separate. Herein, an experimental study is carried out by synthesizing a series of photothermal catalysts composed of Ag nanoparticles supported on TiO2 nanoflake (TNF). The structure of the Ag/TNF was examined by XRD, XPS, and HRTEM, respectively. The local temperature rise of the Ag/TNF was detected during the photothermal reforming reaction of the aqueous bio-glycerol, and its influence on H2 yield was analyzed. By introducing different weight ratios of Ag nanoparticles on TNF, the equilibrium temperature was obviously increased due to the localized surface plasmon resonance (LSPR) effect and dynamic balance between LSPR and heat dissipation was found. It was observed that increasing the weight ratio of Ag particles could result in an increased temperature and lower hydrogen yields. In fact, such photothermal reforming hydrogen production was a synergistic effect between photogenerated-electrons and phonons. Therefore, precisely regulating the photothermal effect by controlling the metal nanoparticles loading to achieve proper thermal balance and high catalytic activity is one effective countermeasure to enhance hydrogen production.