Microkinetic modeling enables a direct comparison of the predicted rates and coverages of distinct surface sites. We note that this information is not easily obtained through experiments, given the site diversity in amorphous silica. Kinetic parameters are predicted from the free energy diagram of the 3CN site, and 10% of the Ga sites in the experimental loading are assumed to be active. We only include the Ga-alkyl-centered C-A cycle because the DFT results have indicated that other cycles will not contribute to the rate or selectivity. With a pure ethylene feed, a conversion of 0.5% is predicted at 523 K and a total pressure of 1 atm, and the turnover frequency (TOF) is 5.7×10 -3 s -1 (with a dilute feed -20% ethylene -an ethylene conversion of 1.4% is obtained at 523 K and a total pressure of 1 atm, and a similar TOF, 3.2×10 -3 s -1 , is observed). The computational values are higher than the experimental value (0.9×10 -3 s -1 ). However, we highlight that the experimental values assume that all Ga sites are active, and hence this value is likely a lower limit on the true turnover frequency. Considering that Ga sites in the synthesized sample are, on average, four-coordinated, a relatively small percentage of 3CN sites are likely to be present in the sample and are responsible for the oligomerization chemistry. Indeed, we predict that the 4CN sites exhibit extremely low turnover frequencies due to the endothermic nature of ethylene physisorption steps, as well as a high barrier of ethylene insertion.