Time-resolved catalysis and ambient pressure photoelectron spectroscopy

More and more evidence suggest that real working catalysts are highly dynamical systems that fluctuate over time with their structure and composition depending crucially on the localized gas-mixture, pressure, and temperature at any given instant.

However, most catalysis studies are performed at static reaction condition.The goal of this project is to go beyond static in-situ studies and study catalyst surfaces exposed to rapid gas-composition, temperature, and pressure pulses.

By the use of so-called event-averaged and time-resolved ambient pressure x-ray photoelectron spectroscopy – a methodology I pioneered – we will correlate surface changes with catalytic activity at the ms time-scale for dynamic bimetallic catalyst systems where both restructuring and segregation occurs.

We will focus on CO and hydrocarbon oxidation as well as CO2 hydrogenation reactions over PtCo, PtNi, and ZnCu based catalysts.In addition, to the event-averaged characterization we will develop a new methodology based spectral analysis in frequency space while simultaneously oscillating reactant gasses and catalyst temperature at different frequencies.

This will allow us to selectively correlate catalyst function with active intermediate minority phases.

Finally, pressure pulses and new instrumentation developed in the project will make x-ray photoelectron spectroscopy experiments possible at 10 bar pressures which is extremely important for the high-pressure ZnCu-based catalyst.