Thermal catalysis The reaction and activation energies of nitrogen oxidation were collected from literature, where the calculations were performed using DACAPO with core electrons described by Vanderbilt ultrasoft pseudopotentials and exchange and correlation effects described by the RPBE functional. The standard entropies of gas molecules are from NIST-harmonic oscillator model. The rate constants of adsorption, surface and desorption reactions were estimated with transition state theory. The steady-state surface coverages and rates were solved with a mean-field microkinetic model, as detailed in Supplementary Methods. The steady-state surface coverages described by ordinary differential equations(ODEs)