Operando Observation of Cu-based Catalyst for Methanol Steam Reforming Process by Ambient-Pressure X-ray Photoelectron Spectroscopy

Cheng-Hao Chuang^1*, Yu-Fu Wang¹, Te-Wei Chiu², A. Knop-Gericke³, J. J. Velasco-Vélez^3,4

¹Department of Physics, Tamkang University, New Taipei City, Taiwan
²Department of Material and Mineral Resources Engineering, National Taipei University of Technology, Taipei, Taiwan
³Department of Inorganic Chemistry, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin, Germany
⁴Department of Heterogeneous Reactions, Max Planck Institute for Chemical Energy Conversion, Mülheim an der Ruhr, Germany

* Presenter:Cheng-Hao Chuang, email:chchuang@mail.tku.edu.tw

Hydrogen has been considered as a promising candidate for the future fuel cell due to the zero-pollutants emission and abundant resource, although the safety storage and transportation become the limitations. Methanol steam reforming (MSR) reaction become known for an attractive and rising process for the hydrogen production, which is commonly activated by copper-based catalyst. The guideline is that water gas reaction and methanol decomposition reaction are happened at the catalytic site, and the intermediate state as CO gas formation make the catalyst poisoned and inactive. The strategy to improve MSR process starts to observe the in-situ chemical reaction with the real environment, if only to compare the catalytic performance without the kinetics condition is not enough. Ambient pressure X-ray photoelectron spectroscopy offers the gas pressure (up to 1 torr range) and mixtures to study the catalytic reaction of CuCrO₂ and CuFeO₂ surface under the realistic conditions. The systematical investigation into the chemical state of heterogeneous surface and adsorbed/dissolved species is found with different probing depths and detection modes. The chemical state (Cu²⁺ and Fe³⁺) of CuCrO₂ and CuFeO₂ under the working temperature is found to be reduced to less oxidation state by active gas species, which is corresponding to the increase of hydrogen gas production. Our project is to observe the chemical evolutions of CuCrO₂ and CuFeO₂ surface using the in-situ control and operando experiment, offering more comprehensive insights and useful information into the green energy application.

Keywords: Methanol steam reforming, Ambient-pressure X-ray photoelectron spectroscopy, Catalysis , Hydrogen generation