Surface-sensitive spectroscopy at atmospheric pressures

Heterogeneous catalysis is critical to the synthesis and purification of chemicals at the industrial scales demanded by modern society, and in mitigating the impact of harmful pollutants on health and the environment by converting them to more inert products. Much of our existing fundamental understanding of the surfaces involved in heterogeneous catalysis relies on studies of model single crystals using surface-sensitive techniques that typically require rarefied ultra-high vacuum (UHV) conditions, and often cryogenic temperatures. However, to truly understand how catalysts operate under industrial process conditions requires working with more complex materials such as nanoparticles (NPs) and at much pressures closer to ambient, respectively referred to as the 'material gap' and 'pressure gap'. In this project, we aim to simultaneously bridge both of these gaps using two specially designed micro-reactors that will enable us to perform surface-sensitive spectroscopies at 1 bar and 200 oC, to reveal the chemical state of NPs, the species absorbed on their surfaces, and the gas phase species.

This project builds on our unique expertise in producing and manipulating graphene, and will take advantage of synchrotron-based XPS at Diamond Light Source, and complementary  polarisation modulation infrared reflection absorption spectroscopy (PM-IRRAS) measurements under atmospheric pressure conditions at the Weizmann Institute of Science.

This project is awarded the Weizmann UK - Making Connection Grant for September 2018-August 2020.

Selected papers:
R. S. Weatherup, B. Eren, Y. Hao, H. Bluhm, M. Salmeron. Graphene membranes for atmospheric pressure photoelectron spectroscopy, J. Phys. Chem. Lett., 7, (2016), 1622-7.