Highly surface sensitive low-energy ion scattering (LEIS) analysis to probe the very outer atomic surface where the reaction takes place in order to explore surface segregation and reconstruction, and determine the key elemental composition for the reaction; X-ray Photoelectron Spectroscopy (XPS) analysis to understand material chemical state; in-situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) analysis to explore the evolution of the surface intermediates formed on materials after annealing treatments with various gas compositions (e.g. CO2, H2 and O2).