Use the date given below to construct a Born-Haber cycle to determine the lattice energy of CaO. Use the data given below to construct a Born-Haber cycle to determine the lattice energy of CaO. We find that the vacancy-formation-energy (VFE) combined with the adsorption energy can be used as a descriptor in the screening of materials that activate doubly and triply bonded molecules that are bound end-on at surface vacancies. 2 Li+ (g) + O2- (g) -> Li2O (s) Place the following in order of decreasing magnitude of lattice energy K2O Rb2S Li2O. The catalytically active surface is one where 3f-hollow-nitrogens are bound to the molybdenum framework with a hexagonal array of embedded Co8 cobalt nanoclusters.
It is shown that these vacancy sites can adsorb and activate N2 demonstrating the potential of a Mars - van Krevelen type mechanism on Co3Mo3N. We show that 3-fold hollow bound nitrogen-containing (111)-surfaces have surprisingly high concentrations (1.6×1016 to 3.7×1016 cm-2) of nitrogen vacancies in the temperature range for ammonia synthesis. We have identified the most favourable sites for surface nitrogen vacancy formation and have calculated vacancy formation free energies (and concentrations) taking into account vacancy configurational entropy and the entropy of N2 at temperature and pressure conditions relevant to ammonia synthesis (380-550 ☌, 100 atm) via a semi-empirical approach. Here we examine whether N2 can adsorb and activate at nitrogen surface vacancies. Co3Mo3N is one of the most active catalysts for ammonia synthesis, however, little is known about the atomistic details of N2 adsorption and activation.
