Dr. Patrick Hemberger

To celebrate contributions of highly influential early and mid-career researchers in energy research, the journal Energy & Fuels established an annual recognition of Energy and Fuels Rising Stars. PSI researcher Patrick Hemberger was selected this year and featured in the current virtual special issue for his contributions in understanding reaction mechanisms in chemistry using advanced synchrotron tools.

Read more: https://www.psi.ch/en/sls/vuv/scientific-highlights/psi-researcher-patrick-hemberger-honored-in-the-rising-stars-special

Mechanistic insights gained by PEPICO spectroscopy helped to enhance selectivity in the zeolite-catalyzed fast pyrolysis of guaiacol. The increased phenol production can be understood by suppressing fulvenone formation through increased Brønsted acid sites density. This approach has wider applicability for optimizing other heterogeneous catalytic processes beyond lignin pyrolysis.

Z. Pan, A. Puente-Urbina, S. Rabia Batool, A. Bodi, X. Wu, Z. Zhang, J. A. van Bokhoven, P. Hemberger* Tuning the zeolite acidity enables selectivity control by suppressing ketene formation in lignin catalytic pyrolysis

Nature Communications  2023, 14, 4512.

Invited perspective on threshold photoelectron spectroscopy as a versatile tool used in heterogeneous catalysis to precisely identify isomer components in reactive mixtures. Case studies demonstrate its effectiveness in understanding complex mechanisms. The technique's robustness, temperature effects, and a novel spectral database, the PhotoElectron PhotoIon Spectral Compendium, are discussed.

P. Hemberger*, Z. Pan, X. Wu, Z. Zhang, K. Kanayama, and A. Bodi. Photoion mass-selected threshold photoelectron spectroscopy to detect reactive intermediates in catalysis: From instrumentation and examples to peculiarities and a database. J. Phys. Chem. C, 2023, 127, 16751–16763.

This study explores propane-to-propylene conversion over boron nitride (BN) catalysts. It identifies a gas-phase route for olefin production involving free radicals and oxygenates, alongside surface-catalyzed processes, with an emphasis on the prevention of CO2 formation by controlling oxygenate desorption from the catalyst surface.

Z. Zhang, J. Tian, X. Wu, I. Surin, J. Pérez-Ramírez, P. Hemberger*, and A. Bodi. Unraveling radical and oxygenate routes in the oxidative dehydrogenation of propane over boron nitride. J. Am. Chem. Soc., 2023, 145, 7910.

First experimental observation of the elusive methylketene as a key intermediate in the production of ethylene during the zeolite-catalyzed methanol-to-olefins reaction. This finding supports a computationally predicted mechanism in which ethylene is generated from ketene through a pathway involving a methylketene intermediate and subsequent decarbonylation

X. Wu, Z. Zhang, Z. Pan, X. Zhou, A. Bodi, and P. Hemberger*. Ketenes in the induction of the methanol-to-olefins process. Angew. Chem. Int. Ed., 2022, 61, e2022077777.

To develop sustainable lignin valorization strategies, a solid understanding of the underlying reaction mechanism is critical. By detection of highly reactive and elusive intermediates, new light could be shed on one of the most basic elementary reactions in lignin catalytic fast pyrolysis.

Z. Pan, A. Puente-Urbina, A. Bodi, J. A. Bokhoven and P. Hemberger* Chem. Sci., 2021,12, 3161–3169 DOI: 10.1039/d1sc00654a

This invited review underscores the significance of clean combustion and carbon neutrality for sustainability. It highlights the use of PEPICO spectroscopy for in-depth mechanistic insights in various chemical processes, including biomass conversion and combustion, and discusses ongoing developments in PEPICO detection tools.

P. Hemberger*, A. Bodi, T. Bierkandt, M. Kohler, D. Kaczmarek, and T. Kasper. Photoelectron photoion coincidence spectroscopy provides mechanistic insights in fuel synthesis and conversion. Energy Fuels, 2021, 35, 16265–26302.

How can we detect reactive and elusive intermediates in catalysis to unveil reaction mechanisms? In this mini review, we discuss novel photoionization tools to support this quest.

P. Hemberger*, J. A. van Bokhoven, J. Pérez-Ramírez, A. Bodi Catal. Sci. Technol., 2020,10, 1975-1990.