In summary, we report a rare example of photochemical H2 activation with a Zn-Fe heterometallic complex. Through a combined experimental, spectroscopic, and computation approach we have interrogated plausible mechanisms for bond breaking of H2. We concluded that there is no unequivocal evidence that supports a single mechanism for the reaction. The combination of experimental and computational data suggests that the heterolytic pathway is unlikely to occur and that other two mechanisms are more probable and may operate simultaneous. One involves photochemical dissociation of CO from the Zn-Fe complex to form a coordinatively saturated intermediate that can react with H2 via oxidative addition and the other involves homolytic cleavage of the Zn-Fe bond to form a pair of radicals that react directly with H2 through a radical pathway.