Which reaction is spontaneous at all temperatures at standard pressure and concentration?

At all temperatures, an exothermic reaction with increasing entropy will be spontaneous. The larger mass of ${\mathrm{CO}}_2$ molecules compared to those of ${\mathrm{O}}_2$ is the primary cause of the positive entropy change. Only at temperatures below those where $\left|\mathrm{T\Delta S}\right|<\left|\mathrm{\Delta H}\right|$, if the reaction is sufficiently exothermic, can it force G negative.