The reactivity of presolvated electrons with CO2 and N2O was studied in the gas pressure range of 1 to 52 bar. To measure this reactivity, a home-made spectroscopic cell with liquid circulation was developed which can work up to 70 bar of gas pressure. The efficiency of presolvated electron scavenging was determined from the decrease of the solvated electron yield after the application of a 5 ps electron pulse. In addition, the reaction rate between these molecules and solvated electrons was directly determined at gas pressures below the gas critical point, which is in agreement with those presented in the literature measured at gas pressures below <1 atm.