The splitting of O2 on transition metal, transition metal carbide, and transition metal oxide surfaces is analyzed in the framework of Bronsted–Evans–Polanyi (BEP) relationships. It is shown that these hold for all three types of substrates, thus giving support to the idea of universality behind these useful relationships. Moreover, comparison of the BEP relationships for the three substrates suggests a significantly higher catalytic activity on metal carbides and rutile metal oxides.