Unravelling CO2 reduction mechanisms on the photocatalyst surface from operando approach

Research division

The use of solar energy to convert CO2 into hydrocarbons could mitigate two main problems : global warming and future energy demand. The photocatalytic route is pertinent, but the process yield remains low even for the most efficient developed materials and many questions stay opened regarding the intrinsic properties of the photocatalyst to be optimized and about the reactional mechanisms.
In this PhD Thesis, we would like to describe the surface mechanisms present on TiO2 (cocatalyst) in the case of a model photocatalytic reaction of interest : CO2 photoreduction in presence of water in gas phase. For that purpose, it will be necessary at first to determine precisely the surface properties of the photocatalysts : hydrophobicity, acido-basicity (semiconductor), metal-support interactions, oxidation state, dispersion (cocatalyst). This could be achieved via in situ IR spectroscopic analysis reactant and probe molecule sorptions. In addition, an operando methodology will be developed using a photoreactor coupled with surface IR analysis. Different effects will be investigated : partial pressure of H2O, CO2/H2O ratio and O2 presence which could strongly impact the photocatalyst selectivity. Reference photocatalysts (different metal loading, acido-basicity, hydrophobicity) will be analyzed in order to bridge the gap between the initial surface properties and the photocatalytic reactivity and to validate the operando IR methodology.

The PhD thesis will be shared between IFPEN – Lyon (samples preparation, conventional analysis and photocatalytic tests) and the Laboratoire Catalyse et Spectrochimie – Caen (operando IR analysis).

Keywords: Solar energy, infrared spectroscopy, photocatalysis, operando

  • Academic supervisor    Dr. EL ROZ Mohamad, Chercheur CNRS, HDR - Laboratoire Catalyse et Spectrochimie (LCS) - Caen
  • Doctoral School    Ecole doctorale Normande de Chimie (EDNC) n°508   
  • IFPEN supervisor    Dr. RIVALLAN Mickaël, Research Engineer, Materials Characterization Division, IFPEN Solaize, mickael.rivallan@ifpen.fr  et Dr. PAGIS Céline, Research Engineer, Catalysis Division, IFPEN Solaize, céline.pagis@ifpen.fr 
  • PhD location    75% Caen (LCS), 25% Solaize (IFPEN)
  • Duration and start date    3 years, starting from October 2020
  • Employer    IFP Energies Nouvelles, Lyon, France
  • Academic requirements    University Master degree or Engineering school in chemical and/or physical sciences
  • Language requirements    Fluency in French or English 
  • Other requirements    Knowledge in vibrational spectroscopy and/or photochemistry


Encadrant IFPEN 
Ingénieur de Recherche, Département Caractérisation des Matériaux
Texte libre

IFP Energies nouvelles is a French public-sector research, innovation and training center. Its mission is to develop efficient, economical, clean and sustainable technologies in the fields of energy, transport and the environment. For more information, see www.ifpen.fr. 
IFPEN offers a stimulating research environment, with access to first in class laboratory infrastructures and computing facilities. IFPEN offers competitive salary and benefits packages. All PhD students have access to dedicated seminars and training sessions.