DESY researcher Fernando Garcia-Martinez received the best oral presentation award at the 38th European Conference on Surface Science ECOSS 38 (Photo: DESY).
Fernando Garcia-Martinez, DESY researcher at the HAXPES beamline P22 at PETRA III, has won the best oral presentation award at the 38th European Conference on Surface Science ECOSS 38 held in Braga, Portugal from 24-29 August 2025.
In his talk on “Structure and pressure gap in the NO reduction reaction on Rh model catalysts studied by operando HAXPES and SXRD”, Fernando showcased how advanced X-ray techniques are crucial for understanding catalytic reactions at industrially relevant conditions. His work focuses on improving the understanding of the reduction of nitric oxide (NO) using Rh catalysts which is key for reducing pollutant emission of combustion engines. The reduction of NO yields mainly harmless nitrogen (N2), but a small amount of dangerous nitrous oxide (N2O) is also produced in catalytic converters. Understanding the mechanism and selectivity of the reaction is therefore of utmost importance to minimise the formation of N2O.
Using ambient-pressure hard X-ray photoemission spectroscopy (AP-HAXPES) at the POLARIS endstation of beamline P22, Fernando and coworkers reveal a significant “pressure gap” in the NO reduction reaction: The production of N2O increases with the total pressure of the experiment. Moreover, they found that the stepped Rh(112) surface is more active and selective towards N2 than the flat Rh(111) facet, demonstrating that the efficiency of NO reduction is strongly dependent on catalyst structure.
To further understand how structure affects the reaction, the research team also performed surface X-ray diffraction (SXRD) at the PETRA III beamline P21.2, showing how Rh steps merge together forming large areas of high-symmetry terraces. These findings highlight the importance of studying the structure of the catalyst under realistic conditions where both chemistry and structure evolve dynamically.
The recognition at the ECOSS 38 conference confirms the relevance of this work to the surface science and catalysis community. Looking ahead, Fernando and his collaborators aim to extend these studies to other catalytic systems and more complex reaction environments. “Understanding reaction mechanisms at the atomic level is of utmost importance for addressing today’s energy and climate challenges,” explains Fernando. “With the state-of-the-art beamlines at PETRA III, we can now study catalysts under conditions closer than ever to those in industry, helping to guide the design of greener and more efficient technologies.”
