We use ambient pressure photoelectron spectroscopy (APXPS), near edge x-ray absorption fine structure (NEXAFS) spectroscopy, and polarisation modulation infrared reflection absorption spectroscopy (PM-IRRAS) to monitor the changes in the chemical state of surfaces as well as the chemical nature, adsorption energies, and adsorption sites of the reactant molecules on surfaces. A critical common trait of all of these techniques is that they can be applied under reaction conditions.
Methanol economy
We are interested in methanol conversion and methanol synthesis reactions on Cu surfaces, which together consititute the carbon-neutral 'methanol economy'.
Selected papers:
J. E. N. Swallow, E. S. Jones, A. R. Head, J. S. Gibson, R. B. David, M. W. Fraser, M. A. van Spronsen, S. Xu, G. Held, B. Eren, R. S. Weatherup. Revealing the Role of CO during CO2 Hydrogenation on Cu Surfaces with In Situ Soft X-Ray Spectroscopy. J. Am. Chem. Soc. 2023
R. Ben David, A. Ben Yaacov, A. R. Head, B. Eren. Methanol Decomposition on Copper Surfaces under Ambient Conditions: Mechanism, Surface Kinetics, and Structure Sensitivity. ACS Catal. 2022, 12, 7709-7718
R. Ben David, A. Ben Yaacov, B. Eren. Effect of Surface Orientation on Methanol Adsorption and Thermally Induced Structural Transformations on Copper Surfaces. J. Phys. Chem. C 2021, 125, 6099-107
B. Eren, C. G. Sole, J. S. Lacasa, D. Grinter, F. Venturini, G. Held, C. S. Esconjauregui, R. S. Weatherup. Identifying the Catalyst Chemical State and Adsorbed Species during Methanol Conversion on Copper using Ambient Pressure X-ray Spectroscopies. Phys. Chem. Chem. Phys. 2020 22, 18806-14
Oil economy
We are interested in understanding the surface chemistry in two reactions. The first one is the Fischer-Tropsch synthesis, which is the conversion of a mixture of CO and H2 into hydrocarbons, typically catalysed by Co-based nanoparticle catalysts in industrial processes. This is a way of producing petroluem-products, alternative to using crude oil. We are currently developing tools to operate APXPS at atmospheric pressure in order to address a few debated questions in the literature regarding the reaction mechanism.
The second project we are interested is the catalytic hydrogenation of alkynes, which is a commercially important reaction used in the purification of alkene streams in the petrochemical industry. We are interested in answering some of the fundamental question regarding ceria-hydrogen interaction and ceria-acetylene interaction.
Selected papers:
B. Eren, A. Head. Carbon Monoxide Adsorption on Manganese Oxide / Cobalt: An Ambient Pressure X-ray Photoelectron Spectroscopy Study. J. Phys. Chem. C 2020, 124, 3557-63
Hydrogen economy
Currenly, oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) are problematic in fuel cell + electrolyser technologies, because of their high overpotentials. We are currently collecting priliminary data on OER on Ni nanoparticles. We have also decided on a research program on how to handle ORR, but we have not started hands-on experiments yet. You can find more on these in a couple of years.
CO2 reduction
We are interested in understanding the CO2 activation and CO2 hydrogenation on Ni surfaces. This is a disputed topic in the literature because Ni is a very active material and small impurities in the gas mixture can change the chemical state of Ni. We are using our spectroscopy tools to understand the intricacies of the CO2-Ni interface, as well as the effect of the common impurities such as water vapour and hydrogen.
We also recently adapted some of our experimental tools to measure the surface chemistry of Cu nanoparticles during the electrochemical CO2 reduction reaction (CO2RR). You can find more on this in a couple of years.