High activity is required so that the near ambient temperature operation can be carried out. The catalyst selectivity is always very important for the reaction. In addition, under the adiabatic operation, there will be a temperature rise in the reactor, therefore, it requires the catalyst to have high selectivity across this temperature range, not only at a narrow temperature range; that is, it requires of high selectivity in a broad temperature range. Last, the catalyst should also have good stability.
Catalyst development were based on OCM reaction mechanism. Oxides which have high methyl radical formation rates are used to enhance catalyst activity. On the other hand, oxides which have low methyl radical stick coefficients are used to enhance catalyst selectivity. Special crystal structure is designed to enhance product diffusion, which will benefit catalyst selectivity. The stability of the catalyst comes from the thermal stability of oxides used under the reaction conditions.
New catalysts system developed demonstrated stable performances which meet or beat the requirement for autothermal, near ambient and adiabatic operation.