On pure Pt, the preferred binding mode for ethylene is di-𝜎 (configuration 1 in Fig. ). This configuration arises from the second most stable isomer of Pt 4 . Importantly, it is found that 8% of the adsorbed ethylene spontaneously dehydrogenates when adsorbing on GM Pt 4 (configuration 4 in Fig. ), making the catalysts prone to coking, since deeper dehydrogenation is essentially unavoidable.