We first show the integrated intensities of the CO2 pulses in H2/CO2/Ar multipulse sequences in Figure . The detected signals and the integrated pulse intensities of the entire multipulse sequence are presented in Figures and, respectively. We also included the size of the CO2 pulses before reaction (incoming pulses) as pink dots in Figure , which was derived from the Ar pulses with the reasonable assumption that the Ar : CO2 ratio in the pulses is constant during the experiment (see Experimental). Furthermore, we assumed that in the final stage of the sequence there is no CO2 consumption except for the very small CH4 formation.